AppNexus
AppNexus's Overview
AppNexus was a pioneering internet technology company that operated a global advertising marketplace and provided enterprise technology for digital advertising. Founded in 2007, it empowered buyers and sellers of digital advertising to innovate and transact. AppNexus offered a comprehensive suite of tools including an ad server, a supply-side platform (SSP), and a demand-side platform (DSP). In 2018, AT&T acquired AppNexus and integrated it into its advertising division, rebranding it as Xandr. Subsequently, in 2022, Microsoft completed its acquisition of Xandr from AT&T. Today, the technology and talent from AppNexus and Xandr are integral parts of Microsoft Advertising, enhancing its offerings in the digital advertising ecosystem, particularly in programmatic advertising and data-driven solutions for buyers and sellers.
Where is AppNexus's Headquarters?
HQ Function
Served as the central hub for executive leadership, core engineering, product development, sales, marketing, and global operations for AppNexus.
Notable Features:
Located in the vibrant Flatiron District, known as a tech hub in NYC. The office space was designed to foster collaboration and innovation, typical of a fast-growing tech company.
Work Culture:
Characterized by a fast-paced, innovative, and engineering-driven environment. Employees often described it as collaborative, with a strong focus on solving complex problems in the ad tech space.
HQ Significance:
The NYC headquarters was pivotal in establishing AppNexus as a major player in the global ad tech industry, particularly within the influential New York advertising market.
Values Reflected in HQ: The headquarters aimed to reflect values of innovation, transparency, learning, and impact, fostering an environment for cutting-edge ad tech development.
Location:
Historically, AppNexus supported global digital advertising operations with a network of offices and data centers across North America, Europe, Asia-Pacific, and Latin America. This allowed them to provide low-latency ad serving, robust platform support, and localized services to clients worldwide. These functions are now integrated into Microsoft Advertising's extensive global infrastructure.
Street Address:
28 West 23rd Street, 11th Floor (Historical)
City:
New York
State/Province:
NY
Country:
USA
AppNexus's Global Presence
London, UK
Address: Specific street address varied over time, typically in tech/media hubs.
To expand AppNexus's footprint in Europe, catering to local publishers and advertisers and navigating regional market dynamics and regulations.
San Francisco, CA, USA
Address: Specific street address varied, often in SoMa or Financial District.
To tap into the West Coast tech ecosystem, drive innovation, and serve clients in the Pacific region.
Hamburg, Germany
Address: Specific street address varied.
To address the specific needs of the German-speaking advertising market, one of the largest in Europe.
Sydney, Australia
Address: Specific street address varied.
To grow AppNexus's presence and serve the burgeoning digital advertising market in the Asia-Pacific region.
Buying Intent Signals for AppNexus
Highperformr Signals uncover buying intent and give you clear insights to target the right accounts at the right time — helping your sales, marketing, and GTM teams close more deals, faster.
Executive Team of AppNexus
As of April 2025, AppNexus' leadership includes:
Investors of AppNexus
AppNexus has been backed by several prominent investors over the years, including:
Executive New Hires/Exits in the Last 12 Months
Since AppNexus was acquired by AT&T to become Xandr, and Xandr was subsequently acquired by Microsoft (completed June 2022), executive changes are primarily within the Microsoft Advertising leadership structure. Specific 'AppNexus' branded executive roles no longer exist. The following illustrates the type of changes that occur within the larger acquiring entity.
Technology (Tech Stack) used by AppNexus
Discover the tools AppNexus uses. Highperformr reveals the technologies powering your target accounts — helping your sales, marketing, and GTM teams prioritize smarter and close faster.
AppNexus Email Formats and Examples
Historically, AppNexus primarily used the [first_initial][last]@[companyname].com format. With its acquisition and integration, direct AppNexus email addresses are no longer active; communications would be through Xandr (phasing out) or Microsoft email domains.
[first_initial][last]@appnexus.com
Format
jdoe@appnexus.com
Example
70%
Success rate
News and media
Microsoft News • December 21, 2021
Microsoft to acquire Xandr to accelerate delivery of digital advertising and retail media solutions
Microsoft announced its agreement to acquire Xandr Inc. from AT&T. Xandr provides a data-enabled technology platform with tools that help power a diverse ecosystem connecting marketers and media owners through a global marketplace....more
Microsoft Advertising Blog • June 7, 2022
Microsoft completes acquisition of Xandr from AT&T
Microsoft announced the completion of its Xandr acquisition, aiming to shape the digital ad marketplace of the future with a focus on trust, transparency, and consumer protection....more
AdExchanger • September 25, 2018
AT&T Officially Rebrands AppNexus As Xandr And Previews Its Addressable TV Solution
AT&T announced that AppNexus, the ad tech company it acquired earlier in the year, would be rebranded as Xandr. The new entity was positioned to combine AT&T's data and content with AppNexus's technology....more
TechCrunch • June 20, 2018
AT&T is acquiring ad tech company AppNexus
AT&T confirmed its acquisition of AppNexus, a major independent ad tech firm. The deal was reportedly valued around $1.6 billion, aiming to bolster AT&T's advertising capabilities....more
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