The news: Publicis Groupe is advising clients that it no longer recommends they use The Trade Desk’s (TTD) demand-side platform, per a memo obtained by Ad Age. Publicis claims that The Trade Desk failed a third-party audit conducted by FirmDecision, which found the company opted users into certain features without consent, improperly charged them, and committed other violations of its master service agreement.

The Trade Desk disputes Publicis’ characterization. “Any notion that TTD failed an audit is not true,” A TTD spokesperson told EMARKETER. TTD said the request included demands for data that would violate customer and partner confidentiality agreements. TTD also said it “is the most transparent, scaled platform in the industry,” that it proposed “a range of options to Publicis,” and that it has had a “long and successful” relationship with Publicis and its clients.

Publicis did not reply to a request for comment in time for publication.

Zooming out: Publicis’ message to clients is one of the most visible cracks yet in a growing rift between agencies and advertising intermediaries.

Agencies are launching a flurry of AI tools and reworking strategies as their industry power diminishes. Those new capabilities include publisher partnerships and direct management of client-publisher relationships, a role typically filled by demand- and supply-side platforms. TTD’s own AI-powered platform, Kokai, has drawn complaints from buyers about a lack of human controls.

Why this matters: The Publicis-TTD conflict reflects the pressure that both agencies and ad exchanges are feeling from tech platforms.

• Meta, Google, Amazon, and others have spent the last two years fleshing out AI ad capabilities, offering brands the ability to create and manage ad campaigns in-platform and directly threatening agencies’ role.
• Meanwhile, TTD has made access to “the open internet” a cornerstone of its business, but EMARKETER data shows that most programmatic spending is happening in walled gardens—platforms that control their own inventory, bidding, and ad tech and are closed to third parties.
• US “open web” programmatic ad spending will reach $40.78 billion this year, up 6.3% YoY. Walled gardens will attract nearly four times that amount at $162.26 billion, up 14.2% YoY.

TTD argues that the rise of walled gardens strengthens its own value proposition, but the company has still publicly clashed with walled-garden DSP providers, including Amazon, in recent months.

Implications for marketers: The growing divide between agencies, third-party exchanges, and tech platforms creates a fragmented programmatic ecosystem for marketers.

Walled gardens, with their broad inventory, user bases, and increased presence in multiple stages of the advertising process, represent ecosystems that advertisers can’t skip out on—even if it means less influence over pricing. As a consequence, agencies and third-party exchanges are left fighting over their scraps.