AppNexus was acquired by AT&T in 2018, rebranded Xandr, then sold to Microsoft in 2022. See its history and current status inside Microsoft Advertising.
AppNexus was a programmatic advertising exchange and technology platform founded in 2007 by Brian O'Kelley and Mike Nolet in New York City. It grew into one of the largest independent ad exchanges, providing both demand-side (buying) and supply-side (selling) technology for digital advertising.
AT&T acquired AppNexus in June 2018 for a reported 1.6 billion US dollars and used it as the foundation for a new advertising unit called Xandr, launched later that year.
In December 2021, AT&T agreed to sell Xandr, including the former AppNexus assets, to Microsoft; the sale closed in June 2022, and Microsoft retired the Xandr brand in 2023, folding the technology into Microsoft Advertising.
The original AppNexus demand-side platform was rebranded first as Xandr Invest and later as Microsoft Invest, providing programmatic ad-buying tools for agencies and advertisers.
Microsoft announced it would shut down Microsoft Invest effective February 28, 2026, moving toward a Copilot-powered, conversational approach to ad buying rather than a traditional DSP interface.
The supply-side and publisher ad serving technology descended from AppNexus continues to operate today under the Microsoft Monetize brand, separate from the now-discontinued demand-side product.
AppNexus does not exist as an independently purchasable product; there is no current AppNexus pricing page, sign-up flow, or standalone brand to evaluate.
Historical AppNexus and Xandr pricing followed typical ad-tech norms, such as percentage-of-spend fees and platform/technology fees, but these are no longer publicly relevant given the brand's retirement.
Businesses looking for equivalent functionality today should evaluate Microsoft Advertising and Microsoft Monetize directly, rather than searching for AppNexus-specific pricing.
Not as an independent brand. AppNexus was acquired by AT&T in 2018, rebranded Xandr, then sold to Microsoft in 2022 and folded into Microsoft Advertising, with the Xandr name retired in 2023.
It became Xandr Invest and later Microsoft Invest; Microsoft announced it would discontinue Microsoft Invest effective February 28, 2026, in favor of a Copilot-powered advertising approach.
The supply-side, publisher-facing ad technology that descended from AppNexus continues to operate under the Microsoft Monetize brand.
AppNexus was founded in 2007 by Brian O'Kelley and Mike Nolet in New York City.
AT&T acquired AppNexus in 2018 for a reported 1.6 billion US dollars to build a national advertising marketplace, which it launched as Xandr.
No. There is no current AppNexus product, pricing page, or sign-up flow; the technology now lives inside Microsoft Advertising and Microsoft Monetize.
Microsoft retired the Xandr name in 2023 and consolidated its advertising technology, including the former AppNexus assets, under the Microsoft Advertising brand.