AT&T’s advertising unit Xandr has finally launched its ad marketplace, called Community.

Community is meant to connect advertisers with “hard-to-reach” audiences whose content consumption has fragmented across platforms, including TV, mobile, online, connected TV and over-the-top.

Xandr sees this as the first step towards a future convergence of linear TV and digital video.

The marketplace will initially include inventory from WarnerMedia’s portfolio of brands including CNN, TNT, TBS, truTV, B/R Live, Warner Bros., along with Vice, Hearst Magazines, Newsy and streaming services Philo, Tubi and Xumo. It will also include inventory from AT&T-owned DirecTV Now.

“After only eight short months since the launch of Xandr, Community delivers on our promise of a brand-safe, insight-driven, premium video marketplace,” said Xandr chief executive officer Brian Lesser said in a statement. “Building on one of the largest technology platforms in the industry and integrating Xandr’s unique audience insights from AT&T, we created the foundation of Community. Now, with the incredible inventory from our inaugural Community partners, the marketplace is open.”

Community will also integrate Xandr’s cross-screen addressable audience solution. Xandr is pitching advertisers that they can define audiences and identify households, and then serve relevant ads to the desired group across screens.

AT&T hopes this will help advertisers reach audiences who are watching fewer ad-supported programs by building out Xandr on its database of 170m AT&T customers.

AT&T recently acquired ad-free HBO as part of its $85bn deal with WarnerMedia, then Time Warner.

Xandr announced the launch of Community at its upfront event today. WarnerMedia will hold its upfront presentation on Wednesday (15 May).