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AppNexus

AppNexus was an multinational that developed and operated a cloud-based software for programmatic , enabling the real-time buying and selling of digital ad inventory across publishers and advertisers. The powered marketplaces for internet advertising, supporting demand-side platforms (DSPs), supply-side platforms (SSPs), and ad exchanges to optimize ad transactions through data-driven automation. Founded in 2007 by Brian O'Kelley and Mike Nolet in , AppNexus emerged from the founders' prior experience at Right Media, an early acquired by . Headquartered in with additional offices worldwide, the company quickly scaled, raising approximately $344 million in funding from investors including WPP, Technology Crossover Ventures, and , and achieving unicorn status with a valuation exceeding $1 billion by 2014. By 2017, AppNexus reported annual revenue of approximately $200 million and employed over 1,000 people globally, establishing itself as a leader in the ad tech sector through innovations in and for ad optimization. In 2018, AT&T acquired AppNexus for approximately $1.6 billion to bolster its advertising capabilities amid its merger with Time Warner, integrating the platform into the newly formed division as its core technology. Under , AppNexus continued to expand but faced challenges in achieving profitability within the telecom giant's broader ad strategy. In December 2021, sold , including AppNexus, to for about $1 billion, rebranding the DSP as Microsoft Invest to integrate with Microsoft's advertising ecosystem. In May 2025, Microsoft announced the shutdown of Invest (formerly and AppNexus) by February 28, 2026, citing a strategic shift toward AI-powered tools and deprioritization of third-party programmatic platforms, resulting in layoffs and the end of the standalone service. Despite its discontinuation, AppNexus's technology significantly influenced the evolution of programmatic , processing billions of ad transactions daily at its peak and setting standards for scalable, cloud-based ad infrastructure.

History

Founding

AppNexus was founded in September 2007 in by Brian O'Kelley and Mike Nolet, both of whom had previously served in key roles at Right Media, an early that was acquired by earlier that year. O'Kelley had been the CTO at Right Media, where he led the development of its exchange technology, while Nolet worked as a and director of analytics, contributing to the platform's real-time capabilities. Their experience at Right Media, which involved scaling infrastructure for high-volume ad transactions, directly informed the new venture's direction. The company's initial purpose was to provide a -based hosting and platform for web applications, targeting industries requiring scalable such as , healthcare, and advertising technology. Drawing from the founders' ad tech background, AppNexus aimed to offer a proto-platform-as-a-service (PaaS) solution that addressed limitations in existing options like early AWS, particularly for applications. This focus evolved from the need for robust, low-latency capable of handling massive volumes, a challenge they had encountered at Right Media. In its early days, AppNexus faced significant challenges in securing initial seed funding and establishing its technical foundation. The founders raised an initial seed round in 2007 from prominent investors including and , which provided crucial capital amid a favorable pre-financial crisis environment. However, the 2008 market crash led to cash constraints, forcing careful while building out data centers and processing systems from scratch. These efforts included developing hardware and software to support high-throughput operations without relying on commoditized cloud providers.

Growth and innovations

Following its founding, AppNexus initially concentrated on developing cloud-based computing to support ad networks and enable more efficient operations, securing early customers among top ad networks by . Between and , the company pivoted toward programmatic , launching its (RTB) ad platform in March , which included an and (SSP) components to facilitate automated ad transactions. This shift allowed AppNexus to process tens of billions of ad impressions monthly by late , equivalent to over ad requests per second, marking a significant scale-up from its roots. To fuel this expansion, AppNexus raised substantial venture funding between 2008 and 2014, totaling more than $230 million across multiple rounds from prominent investors including , Accel Partners, Technology Crossover Ventures (TCV), and others such as First Round Capital and . Key rounds included a $50 million Series C in 2010 led by , a $75 million Series D in 2013 led by TCV, and a $60 million Series E in August 2014 that valued the company at $1.2 billion, achieving unicorn status. These investments supported rapid headcount growth to over 400 employees by 2013 and global office expansions. By 2014, AppNexus had solidified its position as a leading ad tech platform, processing over 34 billion ad impressions daily and facilitating more than $2 billion in annual ad spend. The company expanded its client base to include major publishers such as and a wide array of advertisers, powering significant portions of open-web programmatic transactions. A cornerstone of this growth was AppNexus's development of a RTB engine, which evolved to handle hundreds of thousands of by the mid-2010s, enabling low-latency bidding at massive scale and differentiating the platform in the competitive market. This internal innovation, built on the company's early expertise, supported the platform's ability to manage complex, auctions efficiently without relying on third-party .

Acquisition by AT&T

On June 25, 2018, announced its agreement to acquire AppNexus, a leading programmatic technology company. The deal was completed on August 15, 2018, integrating AppNexus into 's advertising and analytics division. Although the acquisition price was not officially disclosed, reports estimated it at approximately $1.6 billion. The acquisition was strategically motivated by AT&T's recent completion of its $85.4 billion merger with Time Warner on June 14, 2018, which expanded its media assets and heightened the need for advanced advertising tools. AT&T aimed to leverage AppNexus's platform to enhance across television and digital channels, combining it with first-party data from its telecom operations and premium video content from the newly formed . This move was intended to position AT&T as a stronger competitor to digital ad giants like and by enabling more precise, data-driven ad placements. Following the close, AppNexus's co-founder and CEO, Brian O'Kelley, was retained in his leadership role and reported directly to Brian Lesser, CEO of Advertising & Analytics. Initial integration efforts focused on merging AppNexus's technology with 's audience insights and WarnerMedia's content inventory to create synergies for personalized advertising solutions. The deal faced early challenges from regulatory scrutiny, particularly antitrust concerns tied to AT&T's growing media dominance after the Time Warner merger. U.S. Department of Justice efforts to block the Time Warner acquisition referenced AT&T's subsequent moves like the AppNexus deal as potential indicators of anti-competitive consolidation in advertising and content distribution. Despite this, the acquisition proceeded without separate formal challenges, though it amplified broader debates on in the ad tech sector.

Rebranding to Xandr and sale to Microsoft

In 2018, following its acquisition by , AppNexus was rebranded as to consolidate 's advertising operations under a unified platform focused on data-driven solutions integrated across the company's telecommunications and media ecosystem. The rebranding, announced at AT&T's inaugural Relevance Conference, aimed to leverage AppNexus's programmatic capabilities alongside AT&T's vast consumer data from its wireless and services to create personalized ad experiences, with the name "Xandr" serving as a nod to , the inventor associated with AT&T's origins. By mid-2019, had rebranded its core () as Xandr Invest, granting it exclusive access to AT&T's audience data for enhanced targeting across , and connected inventory. Under AT&T's ownership, encountered significant challenges, including high-profile leadership transitions and difficulties in achieving full integration with AT&T's broader assets amid evolving market dynamics. AppNexus co-founder and CEO Brian O'Kelley stepped down from operational duties in October 2018, shortly after the acquisition, transitioning to an advisory role within due to incompatibilities with the . This was followed by the resignation of CEO Brian Lesser in March 2020, amid reports of internal disarray and a broader reorganization of senior executives in September 2019 to streamline leadership. These changes coincided with struggles to monetize AT&T's data synergies effectively, exacerbated by the 2020 shifts in regulations and the pandemic's impact on advertising spend, which undermined the unit's strategic vision and led to perceptions of it as an underperforming investment. On December 21, 2021, agreed to sell to for an undisclosed amount, with the transaction closing in June 2022 after regulatory approvals. The acquisition, reported by some sources to be valued at approximately $1 billion, enabled to integrate Xandr's programmatic technology into , bolstering its and expanding capabilities in connected TV and data-enabled ad buying. Xandr's tools were rebranded as Microsoft Invest, providing advertisers with access to premium inventory and advanced targeting features to compete more effectively in the digital ad market. As of November 2025, has been fully absorbed into , with its legacy AppNexus technologies continuing to underpin key programmatic functions, though Microsoft announced in May 2025 plans to sunset the by February 2026 as part of a strategic pivot toward AI-driven, first-party ad solutions. This integration has enhanced 's overall advertising ecosystem, but the impending DSP closure reflects a deprioritization of third-party programmatic tools in favor of proprietary platforms.

Products and technology

The technology developed by AppNexus formed the core of a full-stack programmatic that powered online ad transactions until its integration into AT&T's division following the 2018 acquisition, and later into Microsoft Invest after the 2021 sale to . Microsoft announced in May 2025 that it would shut down the (DSP) component of Microsoft Invest by February 2026, shifting focus to AI-powered tools, though elements like the (SSP) continued under Monetize.

Core platform

AppNexus operated as a full-stack programmatic platform, integrating an that facilitated connections between publishers and advertisers, a (SSP) for publishers to monetize inventory, and a (DSP) for buyers to purchase ad space efficiently. This architecture enabled seamless transactions in an open marketplace, supporting a wide range of media formats including display, mobile, video, and native ads, without reliance on proprietary walled gardens. The platform's design emphasized and , allowing participants to access the world's largest independent programmatic , which included nearly all top publishers and advertisers by . At the heart of the platform was its (RTB) mechanism, which conducted auctions for ad inventory in under 200 milliseconds to ensure minimal latency during page loads. Using a second-price auction model, the system determined the winner based on the highest bid while charging the second-highest amount plus an increment, promoting fair competition. It accommodated various deal types, including open auctions for broad access, private marketplaces for exclusive inventory, and preferred deals for negotiated pricing, thereby catering to diverse transaction needs in programmatic buying and selling. The platform incorporated (DMP) integration to enhance audience targeting, leveraging first-party data collected from publishers alongside third-party data sources for precise segmentation and personalization. This allowed advertisers to build and activate audience profiles directly within the , such as through dedicated data seats that provided access to proprietary segments without additional external tools. Such integrations supported advanced targeting strategies while maintaining compliance with data privacy standards. Built on a custom cloud infrastructure, AppNexus demonstrated exceptional scalability, processing over 27 billion ad requests daily at its peak to handle high-volume global traffic. This robust backend, optimized for low-latency operations, enabled the platform to manage hundreds of billions of impressions across diverse digital channels without compromising performance. The infrastructure's design supported rapid expansion, as evidenced by strategic additions to reduce auction times for users.

Key features

AppNexus's provided advertisers with frequency capping capabilities, allowing users to set limits on the number of times an ad could be shown to the same individual within a specified period, thereby preventing ad fatigue and optimizing budget allocation. This feature was integrated into setups to ensure controlled exposure across user sessions. The platform supported campaign management, enabling seamless execution across multiple formats including , video, , and connected inventory. This allowed buyers to unify strategies and reach audiences consistently regardless of device or channel, with tools for cross-device targeting to maintain continuity in user experiences. A key component was the private marketplace (PMP), which facilitated direct, invitation-only deals between buyers and sellers, offering access to premium inventory outside open auctions. This bypassed competitive bidding for negotiated terms, providing higher-quality placements and better control over pricing and availability. AppNexus incorporated and for bid optimization, using algorithms to adjust bids in real-time based on performance predictions and market conditions. These technologies also enabled for forecasting campaign outcomes and automated rules for deal execution, such as adjustments in first-price auctions to maximize efficiency. The reporting and analytics dashboard delivered real-time insights into key metrics like spend, impressions, and ROI, with customizable views for monitoring campaign performance. Users could access granular data breakdowns to inform adjustments and evaluate effectiveness across segments.

Innovations in programmatic advertising

AppNexus pioneered the concept of , a technique that enabled publishers to solicit bids from multiple supply-side platforms (SSPs) simultaneously through JavaScript code placed in the webpage header, thereby fostering and optimizing ad . Although the broader adoption surged around 2014, AppNexus CEO Brian O'Kelley claimed the foundational idea originated as early as 2009 under the term "pre-bid," predating widespread industry use. To facilitate implementation, AppNexus developed Prebid.js in early 2015, an open-source framework that standardized header bidding integrations across demand partners, significantly easing deployment for publishers. This innovation allowed many publishers to achieve revenue uplifts of 30-50% by moving away from sequential waterfall auctions toward real-time, unified mechanisms. Building on header bidding, AppNexus extended these principles to through the development of pod bidding, which streamlined auctions for sequential ad breaks (or "pods") in video content streams, enabling more efficient allocation of multiple ad slots within a single break. In 2016, the company launched Prebid Video, an extension of Prebid.js tailored for video, which supported pod-based bidding to reduce and improve fill rates compared to traditional daisy-chain models. AppNexus also advocated for early adoption of server-to-server (S2S) integrations in video header bidding, shifting bid processing from to server-side to minimize page load delays and enhance for high-volume video inventory. AppNexus contributed to open standards in programmatic advertising by co-founding Prebid.org in 2017 alongside Rubicon Project, establishing it as an independent body to govern and advance open-source header bidding technologies, including protocols. The company was an early promoter of IAB Tech Lab's initiative, launched in 2017 to combat domain spoofing and unauthorized inventory sales by allowing publishers to list authorized sellers, thereby enhancing transparency and anti-fraud measures across the . These efforts aligned with broader IAB Tech Lab work on standards like OpenRTB, where AppNexus participated in developing protocols for verifiable impression paths. These innovations profoundly influenced the programmatic landscape, catalyzing a shift from opaque systems to competitive, auctions that pressured incumbents like to introduce analogous features, such as Exchange Bidding, while empowering independent platforms like to gain market share through unified demand access. By democratizing access to premium inventory, AppNexus's technologies fostered greater competition, reduced publisher dependency on single ad servers, and established benchmarks for latency-optimized, fraud-resistant programmatic practices.

Business operations

Leadership

AppNexus was co-founded in 2007 by Brian O'Kelley and Mike Nolet, both former executives at Right Media. O'Kelley served as CEO from the company's inception through 2018, where he emphasized product vision and innovation in programmatic advertising technology. Nolet, as the initial until 2013, led efforts that established AppNexus's core platform architecture. Other key executives during AppNexus's independent phase included Michael Rubenstein, who joined as president in 2010 and oversaw business operations and growth strategies. Ben John succeeded Nolet as CTO in 2013, directing the expansion of the team to over 700 members focused on scalable ad . These leaders contributed to AppNexus's reputation as an -centric in its early years, prioritizing data-driven decisions and technical excellence over traditional sales approaches. Following 's 2018 acquisition, O'Kelley transitioned to an advisory role, while Lesser, a former AppNexus board member, was appointed CEO of the rebranded unit. Lesser led integration efforts until his resignation in 2020 amid 's broader media strategy shifts. Subsequent leadership under featured executives like Shailesh Rao in senior product roles, drawing on ad tech expertise to align with 's advertising ambitions. The AppNexus board during its venture-backed period included representatives from major investors such as , with partners like and providing strategic guidance on scaling and market positioning. Other notable board members were Brian McAndrews, former aQuantive CEO, and Ed Gillis from Accel Partners, who joined in 2012 to bolster governance amid rapid growth. Post-acquisition by in 2021, Xandr's leadership integrated into Microsoft's broader executive structure, with key roles reporting to Microsoft's advertising division heads rather than maintaining a standalone board.

Financing and acquisitions

AppNexus secured its initial venture funding through a Series B round of $8 million in September 2008, led by , Kodiak Venture Partners, and First Round Capital. This was followed by an additional $5 million extension in the same series in November 2009 from the same investors. The company continued raising capital with a $50 million Series C round in October 2010, backed by , Kodiak Venture Partners, First Round Capital, and . A $75 million Series D round followed in January 2013, bringing total funding to approximately $140.5 million at that point. By 2014, AppNexus had raised over $200 million cumulatively through its early- and late-stage rounds, culminating in a Series E investment of $60 million in August from an undisclosed Boston-based public equity and asset management firm, with potential to expand to $100 million. This round closed at $110 million in November 2014, including a $25 million contribution from WPP as part of a . In April 2015, AppNexus raised $62.7 million in a Series F round from undisclosed investors. Subsequent rounds included a $31 million investment in September 2016 from , , and prior backers. Overall, AppNexus raised approximately $381 million across 11 rounds from 2007 to 2016. The Series E round valued AppNexus at $1.2 billion, marking it as a in the ad tech sector. Despite filing confidentially for an IPO in 2016 amid improving market conditions, the company did not proceed with a , citing unfavorable dynamics in the ad tech space influenced by volatile IPO performances of peers like . To expand its capabilities, AppNexus pursued several acquisitions. In 2014, it acquired Alenty, a viewability firm, to enhance ad visibility capabilities. Later that year, it completed the purchase of Open AdStream from Xaxis (a WPP ), integrating advanced ad-serving technology and adding 174 staff. Additional buys included MediaGlu in December 2014 for enhanced mobile video capabilities, Yieldex in March 2015 for yield optimization tools, and Latin America in 2015 to bolster its presence in emerging markets; these moves incorporated expertise from several smaller data and analytics firms. Following its acquisition by in 2018 and subsequent integration into , AppNexus ceased independent financing activities, operating under the parent's resources without separate funding rounds. This structure persisted after acquired in 2021.

Global presence

AppNexus was headquartered in City's Flatiron District, with additional offices in the United States including , opened in 2011 to support West Coast operations, and . The company expanded internationally during the early , establishing a office in 2011 to bolster European presence, followed by a office in 2014 to enter the Australian market, and a office by 2017 as part of broader growth. At its peak before the 2018 acquisition by , AppNexus employed over 1,000 people across its global offices, spanning , , , and . To adapt to regional markets, the company implemented localized strategies, such as launching a GDPR compliance initiative in 2017 that involved reviewing and restricting partners to ensure data privacy standards in . In , AppNexus formed a with in 2016, including a $10 million , to integrate its programmatic tools with local publishers and enhance . Following the rebranding to and Microsoft's 2021 acquisition, which closed in 2022, the workforce integrated into , bringing over 1,000 employees initially focused on ad technology. By 2025, under , operations have become primarily U.S.-centric, with the standalone international footprint significantly reduced after the announcement to sunset the DSP (formerly AppNexus) by February 2026, shifting emphasis to AI-driven advertising within Microsoft's ecosystem.

References

  1. [1]
    AppNexus - Crunchbase Company Profile & Funding
    AppNexus operates a cloud-based software platform that enables and optimizes programmatic online advertising.
  2. [2]
    AppNexus Inc - Company Profile and News - Bloomberg Markets
    AppNexus Inc. operates as a trading solutions and powers marketplaces for internet advertising company.
  3. [3]
    AppNexus 2025 Company Profile: Valuation, Investors, Acquisition
    Developer of an internet technology platform that enables and optimizes the real-time sale and purchase of digital advertising.
  4. [4]
    AppNexus | Company Overview & News - Forbes
    Months after reportedly filing confidentially for an IPO in November 2016, New York company AppNexus is looking to machine learning to try to stay ahead.
  5. [5]
    https://www.wsj.com/articles/at-t-in-talks-to-acquire-appnexus-for-about-1-6-billion-1529464400
  6. [6]
    Xandr, Formerly AppNexus, Is Now Formerly AT&T, After Its ...
    Dec 21, 2021 · AT&T has sold its ad tech business Xandr to Microsoft. Terms of the deal were not disclosed. The acquisition marks the end of a painful and unsuccessful run.
  7. [7]
    AT&T Sells Xandr Ad Business to Microsoft for $1 Billion
    Dec 21, 2021 · AT&T Sells Xandr Ad Business to Microsoft for $1 Billion. Carrier sought buyer for non-core unit for more than a year; Xandr was formed in 2018 ...
  8. [8]
    Microsoft Is Shutting Down Invest, The One-Time AppNexus DSP ...
    May 14, 2025 · Microsoft has deprioritized the third-party programmatic business ever since it acquired Xandr from AT&T in 2021. (The deal closed in 2022 ...
  9. [9]
    New King Of Ad Tech: How AppNexus CEO Brian O'Kelley ... - Forbes
    Jun 26, 2013 · ... O'Kelley, who then started AppNexus in September 2007 with former Right Media exec Mike Nolet. The Prompt: Get the week's biggest AI news on ...
  10. [10]
    48. Brian O'Kelley (part 3) – the AppNexus adventure - Paleo Ad Tech
    Dec 10, 2023 · He didn't contemplate for long, co-founding AppNexus in 2007 with Mike Nolet, a young product manager at Right Media.
  11. [11]
    Inside One Of New York's Greatest Startup Success Stories, AppNexus
    Nov 3, 2011 · AppNexus was founded in 2007 by Brian O'Kelley and Mike Nolet. Both were early members of ad exchange Right Media, which sold to Yahoo at an $ ...
  12. [12]
    AppNexus' First Pitch — Before It Steered Around the Cloud to Win ...
    AppNexus opens the vault and shares its very first seed funding pitch deck, created before its impressive pivot.Missing: Andreessen Khosla
  13. [13]
    Billion Dollar Unicorns: AppNexus Found An Exit | Sramana Mitra
    Jul 3, 2018 · Till recently, AppNexus was venture funded with $321.5 million in funding from investors ... Khosla Ventures, and Marc Andreessen. In ...
  14. [14]
    [PDF] June 22, 2008 Appnexus MFT/BDA (New York City) Overview
    computing infrastructure to enable a more efficient advertising ecosystem. The company has built its cloud platform and has 20 customers including 15 ...
  15. [15]
    AppNexus Officially Launches Ad Platform Fueling the Real-Time ...
    Mar 12, 2010 · AppNexus Officially Launches Ad Platform Fueling the Real-Time Bidding Revolution in Display Advertising. Offers single-point integration with ...Missing: engine innovation
  16. [16]
    [PDF] 1 Before the Federal Trade Commission Washington, DC In the ...
    AppNexus explained that its ad buying platform was serving “tens of billions of advertising impressions per month (over 30,000 ad requests per second),” and.Missing: queries | Show results with:queries
  17. [17]
    AppNexus' $100 Million Investment Values It at $1.2 Billion
    Aug 18, 2014 · AppNexus, the New York-based adtech giant, has taken a round of investment of up to $100 million that values the company at $1.2 billion, ...
  18. [18]
    AppNexus Secures $50 Million In Growth Capital Financing to Fuel ...
    Oct 5, 2010 · PRNewswire/ -- AppNexus today announced that it has raised $50 million in Series C funding for its rapidly-growing real-time ad platform.Missing: 2008-2014 | Show results with:2008-2014
  19. [19]
    AppNexus Raises $75 Million - Business Insider
    Jan 24, 2013 · AppNexus today announced it has raised $75 million in Series D funding led by Technology Crossover Ventures (TCV), one of the largest growth equity firms ...Missing: 2008-2014 | Show results with:2008-2014
  20. [20]
    AppNexus Raises $60M Round Valuing The Ad-Tech Company At ...
    Aug 18, 2014 · Waabi: In June 2024, the autonomous trucking startup raised a $200 million Series B round co-led by existing investors Uber and Khosla Ventures.Missing: initial | Show results with:initial
  21. [21]
    AppNexus Secures $75 Million After Long Road To Funding
    Jan 24, 2013 · AppNexus media spend measured $700 million in 2012 (triple its 2011 revenues) and the company doubled its headcount to 400 globally. The company ...Missing: 2008-2014 | Show results with:2008-2014
  22. [22]
    AppNexus Closes 2014 With Record Profitability, Revenue Growth ...
    Dec 22, 2014 · Total estimated 2014 ad spend on the AppNexus platform will exceed $2 billion, with over 34 billion ad impressions per day in 2014.
  23. [23]
    AppNexus Acquires Yieldex, Publisher Forecasting And Pricing ...
    Mar 18, 2015 · Eight-year-old Yieldex lets publishers forecast, price and sell their inventory. Its customers include The New York Times, Expedia, Pandora, CBS ...
  24. [24]
    How many queries per second get an ad exchange? Is there ... - Quora
    Sep 6, 2017 · Typically, ad exchanges handle a few hundred thousand queries per second (QPS) - or rather auctions per second.What is exactly the meaning of QPS (query-per-seconds) in RTB ...What unforeseen problems might I encounter while implementing a ...More results from www.quora.com
  25. [25]
    AT&T confirms it is buying ad platform AppNexus, reportedly for ...
    Jun 25, 2018 · AT&T confirms it is buying ad platform AppNexus, reportedly for between $1.6B-$2B. Ingrid Lunden. 5:43 AM PDT · June 25, 2018.
  26. [26]
    AT&T Completes Acquisition of AppNexus - citybuzz
    Aug 15, 2018 · With the acquisition now closed, AppNexus' co-founder and CEO Brian O'Kelley will report directly to Lesser. He will continue to lead the ...
  27. [27]
    Investors are torn over whether AppNexus's sale to AT&T was a ...
    Jun 30, 2018 · AT&T has purchased the digital ad firm AppNexus for an undisclosed amount, though reports peg the exit price at about $1.6 billion.
  28. [28]
    Agrees to Acquire AppNexus - SEC.gov
    "Since we closed the Time Warner deal, we've also announced an agreement to acquire ad-tech leader AppNexus, which will be an important step to ...Missing: motivation challenges
  29. [29]
    AT&T to acquire AppNexus - TelecomTV
    Jun 26, 2018 · AT&T will continue to invest in and build on AppNexus' foundational technology as it integrates with AT&T's first-party data, premium video ...
  30. [30]
    AT&T to buy online ad firm AppNexus - CNBC
    Jun 25, 2018 · AT&T said on Monday it would buy online advertisement exchange company AppNexus, less than a month after the No. 2 U.S. wireless carrier closed ...
  31. [31]
    Fresh off its Time Warner win, AT&T is buying yet another company
    Jun 26, 2018 · The deal could face regulatory scrutiny: Policymakers have previously signalled that competition is best preserved when consumers have access to ...<|control11|><|separator|>
  32. [32]
    District Court Rejects DOJ Efforts to Block AT&T Acquisition of T
    Aug 16, 2018 · The opinion is a 172 page tour-de-force on the state of the video programming industry and where things are headed, and how vertical ...
  33. [33]
    AT&T may have what it needs to challenge Google's advertising ...
    AT&T may have what it needs to challenge Google's advertising business. During its antitrust trial this year, AT&T described itself as a legacy TV company ...Missing: scrutiny | Show results with:scrutiny
  34. [34]
    AT&T Unveils Xandr, Its Newly Rebranded Ad-Tech Unit - ADWEEK
    Sep 25, 2018 · AT&T today announced the rebrand of its AdCo unit, unveiling Xandr at its inaugural Relevance Conference in Santa Barbara, Calif.
  35. [35]
    AT&T Ad Unit Now Called `Xandr' in Nod to Alexander Graham Bell
    Sep 25, 2018 · AT&T Inc. named its new advertising and analytics division “Xandr,” making it the home of technology businesses including AdWorks and AppNexus.<|separator|>
  36. [36]
    AT&T names new advertising company "Xandr" - Axios
    Sep 25, 2018 · AT&T is naming its new advertising company "Xandr," combining AT&T's advertising infrastructure, as well as assets from its recent Time ...Missing: rebranding | Show results with:rebranding
  37. [37]
    Xandr Rebrands AppNexus DSP To 'Xandr Invest,' Gives It Exclusive ...
    Jun 10, 2019 · Xandr is making AT&T data available to buyers across all media types through AppNexus's demand-side platform (DSP), which it has rebranded as Xandr Invest.
  38. [38]
    Brian O'Kelley Steps Down As AppNexus CEO - AdExchanger
    Oct 5, 2018 · AppNexus co-founder and CEO Brian O'Kelley has stepped down from his operational role and will serve in an advisory capacity at Xandr, the AT&T- ...
  39. [39]
    Xandr has lost its CEO | Advertising - Campaign Asia
    Mar 12, 2020 · The chief executive of AT&T's advertising unit Xandr has reportedly resigned, in a move that has shocked the industry. Brian Lesser was ...
  40. [40]
    Xandr Reorganizes Senior Execs to Create Single Voice | Next TV
    Sep 23, 2019 · AT&T's Xandr ad unit reorganized its senior management following the departure of several top executives.
  41. [41]
    Microsoft buys Xandr, ending AT&T's ad tech bet that never ... - Digiday
    Dec 21, 2021 · Xandr also suffered from a number of key senior departures with AppNexus' talismanic CEO Brian O'Kelley exiting just weeks after the sale to ...
  42. [42]
    Microsoft to acquire Xandr to accelerate delivery of digital ...
    Dec 21, 2021 · Microsoft is announcing that we have entered an agreement to acquire Xandr from AT&T. Xandr provides a data-enabled technology platform with tools that help ...
  43. [43]
    Microsoft, AT&T's Xandr acquisition complete - Search Engine Land
    Jun 6, 2022 · On December 21, 2021 Microsoft announced that plans to acquire Xandr from AT&T. Six months later Microsoft has disclosed that the acquisition has been ...
  44. [44]
    AT&T sells Xandr ad business to Microsoft for $1 billion
    Dec 21, 2021 · The deal is valued at about $1 billion, according to people familiar with the matter who asked not to be identified discussing nonpublic ...
  45. [45]
    Microsoft Advertising is closing the Xandr DSP, layoffs pending
    May 14, 2025 · Microsoft Advertising is closing its DSP, with the online giant informing clients the ad tech unit no longer aligns with its AI priorities.
  46. [46]
    Microsoft to sunset Xandr DSP - PPC Land
    May 14, 2025 · Under O'Kelley's leadership, AppNexus adopted a strategy called supply path optimization (SPO) that allowed it to benefit from having a low take ...Missing: struggles | Show results with:struggles<|separator|>
  47. [47]
    Appnexus DSP & Appnexus SSP | What is Appnexus | Gourmet Ads
    Jan 1, 2024 · The Appnexus DSP and the Appnexus SSP as our primary SSP & Ad Server. Appnexus handles Programmatic buying across Gourmet Ads.Missing: 2008-2010 | Show results with:2008-2010
  48. [48]
    How Agencies And AdTech/MarTech Companies Can Benefit From ...
    AppNexus first appeared on the online advertising scene in 2007 as an ad exchange for programmatic media buying. Since then, it has morphed into one of the ...
  49. [49]
    AppNexus Expands Real-time Bidding Globally With New Data ...
    AppNexus Expands Real-time Bidding Globally With New Data Center in the Netherlands ... real-time bidding ... milliseconds to much of Europe. ABOUT APPNEXUS.
  50. [50]
    The AppNexus Ad Platform: Building for Scale with NoSQL, MySQL ...
    Nov 12, 2012 · With 2000% growth in 2011, tens of millions of dollars of transactions ... AppNexus system that handles over 27 billion ad requests a day.
  51. [51]
    [PDF] Viral Content: The First Warning Sign of Fraud
    As the world's leading independent ad tech platform, AppNexus sees hundreds of billions of impressions each day, across every corner of the digital ecosystem.
  52. [52]
    Digital Platform API - Ad Profile Service | Microsoft Learn
    Oct 22, 2025 · In this article, learn about Digital Platform API's Ad Profile service, their JSON fields, and REST API with thorough examples.
  53. [53]
    AppNexus Programmable Platform - SaaSworthy
    Uses AI and machine learning to maximize a campaign's performance. Frequency Capping ... Sends instant status reports about the task with customer feedback.
  54. [54]
    AppNexus Dives Into Connected TV - AdExchanger
    May 4, 2017 · ... omnichannel” publishers with a mix of new native, mobile and video monetization, Hoffert said. Microsoft was a charter partner for AppNexus ...<|separator|>
  55. [55]
    MobileFuse Teams With AppNexus For Programmatic, Private ...
    ... AppNexus For Programmatic, Private Marketplace. by Ben Frederick , May 24, 2016. MobileFuse, a mobile ad network, announced a partnership with AppNexus today ...
  56. [56]
    AppNexus Launches the AppNexus Programmable Platform, the ...
    Nov 6, 2017 · APP harnesses advanced machine learning to help professional traders execute highly customized and complex strategies through a seamless user ...
  57. [57]
    AppNexus launches ad industry's first programmable demand side ...
    Nov 6, 2017 · AppNexus is hoping to shake up the world of buy-side advertising with the industry's first programmable demand side platform (DSP). The AppNexus ...
  58. [58]
    'I Invented Header Bidding': Now O'Kelly Is Making Marketing ...
    Sep 23, 2016 · In the words of the AppNexus CEO himself: “I invented header bidding back in 2009.” Using that technology, publishers don't have to be ...
  59. [59]
    Who Invented What in Ad Tech? - Part Two - VideoWeek
    Jun 29, 2018 · Beeswax's Ari Paparo however backs up Brian O'Kelley's claim that he invented header bidding back in 2009, which AppNexus called 'pre-bid'.
  60. [60]
    About Prebid.js for Header Bidding
    Prebid.js was created in early 2015 by Matt Kendall and Paul Yang from AppNexus, together with the help of Nick Jacob from the publisher Aplus.Missing: pioneered | Show results with:pioneered
  61. [61]
    With header bidding, publishers are boosting CPMs by as ... - Digiday
    Nov 12, 2015 · With header bidding, publishers are boosting CPMs by as much as 50 percent. Ad tech acolytes are hyping header bidding as a way for publishers ...
  62. [62]
    Time to Press Play on Header Bidding for Video
    And whether you're using header bidding or a waterfall setup, providers like AppNexus can also audit creatives for content and potentially page-impacting.Missing: invention | Show results with:invention
  63. [63]
    AppNexus Launches PreBid for Video Advertising - PR Newswire
    Dec 15, 2016 · AppNexus' video header bidding technology is now available in beta on GitHub, including prebid.js source code, documentation on how to integrate ...
  64. [64]
    HEADER BIDDING:
    As header bidding creates a real-time marketplace for native ads, more and more brand dollars will flow into the space, creating a superior user experience ...
  65. [65]
    Prebid.org Launches as an Independent Organization for Open ...
    Sep 11, 2017 · "The formation of Prebid.org marks a crucial step forward in the push for industry-wide adoption of open-source header bidding technologies," ...
  66. [66]
    AppNexus Enforces Ads.txt in Broader Push for Industry Transparency
    Feb 28, 2018 · The company was an early promoter of ads.txt, the IAB initiative that gives publishers a standardized way to publicly list all of their ...
  67. [67]
    AppNexus Rolls Out Publisher Suite To Take On Google
    Nov 4, 2015 · AppNexus unveiled a publisher suite Wednesday designed to offer an alternative to DoubleClick for Publishers [DFP], the dominant solution in the market.
  68. [68]
    'An ad tech urban legend': An oral history of how header bidding ...
    Jun 16, 2017 · DeWitt: Sometime in 2014, a header-bidding Slack channel started that publishers used to share insights. I give that Slack channel and ...Missing: AppNexus | Show results with:AppNexus
  69. [69]
    AppNexus CEO Brian O'Kelley to step down and take on 'advisory role'
    Oct 5, 2018 · O'Kelley co-founded it in 2007 with Mike Nolet, who stepped down as chief technology officer in 2013. AT&T declined to make any comment when ...
  70. [70]
    AppNexus Co-Founder Brian O'Kelley on The Future of Mobile ...
    Oct 8, 2013 · And at what point did your co-founder Mike Nolet become involved? Mike called me in 2005. We both went to Princeton, I was [there] ...Missing: background | Show results with:background
  71. [71]
    Interview with Michael Rubenstein, President of AppNexus - Nasdaq
    Oct 3, 2018 · Michael Rubenstein: So AppNexus was started in 2007 by our co-founders Mike Nolet and Brian O'Kelley, I joined two years later. The vision ...
  72. [72]
    Xandr's Ben John: Engineering the Organization - MediaVillage
    Jun 4, 2019 · He joined AppNexus six years ago and helms the 700+ person team of employees and consultants that creates and manages technology offerings like ...
  73. [73]
    Managing engineering at scale - CTO Connection
    In this wide ranging talk, I chat with Dr. Ben John about his experiences in scaling and managing the team at AppNexus (and post AT&T acquisition at Xandr).
  74. [74]
    AppNexus Co-Founder Steps Down as CEO Following AT&T ...
    Oct 5, 2018 · O'Kelley will move to an advisory role within Xandr, according to reports citing sources familiar with the reorganization. This will also see ...
  75. [75]
    Exclusive: CEO of AT&T ad unit Xandr resigns - source - Reuters
    Mar 11, 2020 · Brian Lesser, chief executive of AT&T Inc's <T.N> advertising unit Xandr, has resigned, a source familiar with the matter said on Wednesday, ...Missing: acquisition | Show results with:acquisition
  76. [76]
    Shailesh Rao - Arc180 - LinkedIn
    Experience: Arc180 · Education: Kellogg School of Management · Location: United States · 500+ connections on LinkedIn. View Shailesh Rao's profile on LinkedIn, ...Missing: Xandr AT&T
  77. [77]
    Brian McAndrews and Ed Gillis Join AppNexus Board of Directors
    Nov 7, 2012 · Brian McAndrews and Ed Gillis Join AppNexus Board of Directors ... Andreessen, Ben Horowitz and Ron Conway. For more information, visit ...
  78. [78]
    AppNexus Appoints Two New Board Members | PE Hub
    AppNexus Appoints Two New Board Members. Angela ... Andreessen, Ben Horowitz and Ron Conway. PRESS ... Gillis is also a member of the board of directors ...
  79. [79]
    Series B - AppNexus - 2008-09-16 - Crunchbase Funding Round ...
    AppNexus raised $8000000 on 2008-09-16 in Series B.
  80. [80]
    AppNexus Funding Rounds | Startup Ranking
    AppNexus Funding Rounds ; Nov 01, 2009, Series B · $ 5,000,000. Venrock · Kodiak Venture Partners · First Round Capital ; Sep 01, 2008, Series B · $ 8,000,000.Missing: early | Show results with:early
  81. [81]
    AppNexus advertises $75m round -
    Jan 27, 2013 · Bloomberg said AppNexus's investors also included angels Marc Andreessen and Ron Conway. Bloomberg is an investor in Andreessen's venture ...
  82. [82]
    AppNexus closes series E at $110m - - Global Corporate Venturing
    AppNexus closes series E at $110m. Nov 4, 2014 • Robert Lavine ... WPP contributed $25m to the round, which supported the acquisition of its subsidiary OAS ...Missing: unicorn | Show results with:unicorn
  83. [83]
    NewsCorp just pumped $10 million into ad tech company AppNexus ...
    Sep 28, 2016 · Ad tech company AppNexus has raised a $31 million funding round, which includes a $10 million investment from News Corp, involvement from Yahoo ...Missing: history | Show results with:history<|control11|><|separator|>
  84. [84]
    2025 Funding Rounds & List of Investors - AppNexus - Tracxn
    Oct 16, 2025 · AppNexus has raised a total of $319M over 10 funding rounds: 1 Seed, 2 Early-Stage and 7 Late-Stage rounds. AppNexus' largest funding round so far was a Series ...Missing: Telstra | Show results with:Telstra
  85. [85]
    Now Profitable, AppNexus Scores $1.2 Billion Valuation For New ...
    Aug 18, 2014 · AppNexus knows venture investors well, having raised more than $200 million to date from firms like Andreessen Horowitz, Khosla Ventures, First ...
  86. [86]
    https://www.forbes.com/sites/alexkonrad/2014/08/18/now-profitable-appnexus-scores-1-2-billion-valuation-for-new-york-ad-tech-scene/
  87. [87]
    What Happened to the Missing AppNexus IPO - Business Insider
    such as Snapchat — poisoned the market, so AppNexus is biding its time. "The ...
  88. [88]
    AppNexus Draws Closer To IPO By Acquiring MediaGlu, Its ... - Forbes
    Dec 18, 2014 · The MediaGlu acquisition, though small by headcount–just six staffers, compared to 174 at Open AdStream and 25 at Alenty–helps bolster AppNexus' ...
  89. [89]
    AppNexus Completes Open AdStream® Acquisition and Closes ...
    Oct 31, 2014 · On September 22, 2014, the company announced that it would acquire OAS®, formerly known as Xaxis For Publishers, in a strategic transaction with ...Missing: Alenty | Show results with:Alenty
  90. [90]
    AppNexus to Buy RealMedia to Step-Up LATAM Growth
    Jun 15, 2015 · AppNexus is to purchase Brazil-based RealMedia Latin America (RMLA) for an undisclosed fee – bringing its acquisition-count to five in the last year.
  91. [91]
    AppNexus Carves out West Coast Presence by Opening Seattle Office
    Aug 25, 2011 · Global Sites. APAC · APAC - Simplified Chinese · APAC - Traditional Chinese · Brazil · Canada · Czech · Denmark · Finland · France · Germany ...<|control11|><|separator|>
  92. [92]
    AppNexus - Products, Competitors, Financials, Employees ...
    In June 2018, AppNexus was acquired by AT&T at a valuation between $1.6B and $2B. Headquarters Location. 28 West 23rd Street 4th Floor. New York, New York ...Missing: global history
  93. [93]
    AppNexus Deepens Investment In The United Kingdom With Hire of ...
    AppNexus' London office opened in July 2011 and is one of four global offices, including the company's New York headquarters, Seattle, and Tel Aviv ...
  94. [94]
    AppNexus expands into Australian market - Mumbrella
    Mar 18, 2014 · AppNexus has announced its expansion into the Australian market with the opening of a Sydney office. The New York based company has ...Missing: timeline London Tokyo
  95. [95]
    [PDF] united states securities and exchange commission - form 10-k
    Mar 3, 2022 · 2015: Acquired Veenome; continued international expansion with office openings in Australia, France, and Japan. 2016: Announced industry ...
  96. [96]
    AppNexus Launches Initiative To Drive Toward GDPR Compliance
    As part of its initiative, AppNexus will review the list of partners with whom it works, either directly or through its customer relationships, and will impose ...Missing: Australia | Show results with:Australia
  97. [97]
    AppNexus announces News Corp as new strategic partner
    Sep 29, 2016 · AppNexus announces News Corp as new strategic partner. September 29 ... SSP and Yieldex Analytics, including Dow Jones, News UK and News ...
  98. [98]
    Microsoft Is Deprioritizing Third-Party Ad Tech Amid Reorgs And ...
    Jun 6, 2023 · Microsoft's purchase of Xandr from AT&T in late 2021 might have looked like an embrace of third-party ad tech. But while parts of the Xandr ...