AT&T Inc.

Major telecommunications provider with scaled-back AdTech operations following Xandr divestiture

AT&T Inc. is a multinational telecommunications conglomerate that has played a significant role in the advertising technology ecosystem, primarily through its ownership and development of Xandr, a sophisticated programmatic advertising platform. Following its acquisition of AppNexus in 2018 for approximately $1.6 billion, AT&T rebranded the platform as Xandr and integrated it with its vast telecommunications data assets to create advanced audience targeting and programmatic advertising solutions. The company leveraged its position as one of the largest telecommunications providers in the United States, with access to extensive first-party data from millions of subscribers, to offer advertisers unique targeting capabilities across connected TV, mobile, and digital channels. In 2021, AT&T sold Xandr to Microsoft for an undisclosed amount, marking its exit from the direct AdTech platform business. However, AT&T continues to participate in the advertising ecosystem through AT&T Advertising, which focuses on leveraging the company's media properties and customer data for advertising solutions. The company's advertising business now primarily supports its own media assets and provides data-driven advertising opportunities across its telecommunications network. While AT&T has scaled back its AdTech ambitions following the Xandr divestiture and the spin-off of WarnerMedia (which merged with Discovery to form Warner Bros. Discovery), it remains a significant player in telecommunications-based advertising and data services.