John Wren spent most of his April 28 earnings call talking up cost synergies from the Interpublic Group merger that closed earlier this quarter. Then, in a stretch of the Q&A about AI strategy, he pivoted to a sentence that should have been the lede on every trade-press piece that followed. “There aren’t too many major groups that are looking to have more direct relationships with the publishers,” Wren said. “That is an objective.”
Paolo Yuvienco, Omnicom’s CTO and AI Officer, filled in the mechanics in the same exchange. The combined Omnicom-IPG holdco, now the largest by revenue, is running live agent-to-agent media buys “for several clients” using the Ad Context Protocol, an emerging open-spec framework that lets advertiser-side AI agents and publisher-side AI agents negotiate and transact ad inventory directly. No DSP. No SSP. No exchange in the middle. Wren named the intermediaries Omnicom is routing around as a “toll,” one “paid for by clients and by the industry itself.”
The independent ad-tech stack has worried about a version of this since the ANA published its programmatic supply-chain transparency study in 2022 and found that advertisers were getting roughly 36 cents on the dollar in working media on the open exchange. That number is a six-year-old grievance with a new operational answer.
What changed isn’t the protocol. It’s who’s using it.
Direct-publisher PMP and programmatic-guaranteed deals aren’t new. The shift from open-exchange RTB to negotiated direct deals has been a five-year-long arc; per IAB and eMarketer estimates, the share of US programmatic spend transacted as PMP/PG climbed from under 20 percent in 2020 to roughly 45 percent in 2025. What’s new in Omnicom’s announcement is the layering of agent-to-agent automation on top of that direct-deal substrate. The thing the trade press has been calling “agentic advertising” for the past 18 months, mostly as keynote-stage conjecture, Omnicom now says is in production.
A few markers separate this from the previous wave of “we’re going direct” holdco announcements:
- It’s the post-merger Omnicom, not pre-merger. Combined with IPG, the holdco’s bargaining weight in any direct-publisher conversation is materially larger. Scale changes which conversations get returned.
- Acxiom is the spine. Wren defended the 2018 Acxiom acquisition on the call as the long bet that aged into the right moment. Acxiom’s first-party data layer is what Omni, Omnicom’s AI marketing platform, uses to construct the audience and creative inputs that the agents trade against.
- AdCP is positioned as open, not proprietary. Yuvienco described AdCP as the framework Omnicom is building Omni’s agentic capabilities around, not a closed Omnicom-owned standard. The IAB Tech Lab has been the loose convener of similar agentic-protocol discussions through 2025 and 2026; see the PGC and LEAP launches covered last week.
- It’s been “tested” with real client buys. “Tested the pipes” was Yuvienco’s verbatim phrase. Not a sandbox, not a demo. Live spend.
There aren’t too many major groups that are looking to have more direct relationships with the publishers. That is an objective.
The sentence Wren delivered with characteristic flatness, “that is an objective,” is the one the independent ad-tech stack has to read carefully. The disintermediation thesis isn’t a position paper anymore.
The exposure map runs through the Q2 calls
The independent ad-tech companies most exposed to a meaningful holdco-direct shift are the same ones the trade press has spent the past quarter analyzing on other axes:
- The Trade Desk is the most exposed of the independent DSPs. Omnicom is a major TTD client. Jeff Green’s April 29 AdWeek interview, the day after Omnicom’s call, landed with the line “we want to help” agencies after months of tension over Ventura and supply-path control. Read that as response posture, not coincidence.
- Magnite, PubMatic, OpenX are the independent SSPs whose take rate sits between publishers and DSPs. Direct holdco-to-publisher agentic buys bypass the SSP layer entirely. Both Magnite and PubMatic report Q1 results in early-to-mid May; analyst questions on holdco-direct exposure are now table stakes.
- DoubleVerify, Integral Ad Science, MOAT are verification vendors, less exposed. Agentic buys still need post-buy verification, and the audit case may actually strengthen as the buying layer becomes more opaque to humans.
- Premium publishers with first-party-data and direct-sales operations are the indirect beneficiaries. Disney, NBCUniversal/Versant, Warner Bros. Discovery, Paramount, the New York Times, Hearst, the Roku Channel: all the entities that have been investing in clean-room and direct-data infrastructure now have a holdco partner publicly committed to spending against that infrastructure without a DSP toll.
- Walled gardens are largely insulated. Google, Meta, Amazon, YouTube; the inventory is sold through their own platforms. Agentic protocols would interact with them through existing APIs, not bypass them.
What this isn’t (yet)
A few honest qualifications, since the trade-press temptation is to over-read.
Omnicom did not name which publishers are on the AdCP rails. Wren and Yuvienco did not quantify the share of Omnicom’s total media spend that’s running through agent-to-agent rails today (almost certainly small). They did not name which DSPs and SSPs are being bypassed (probably some, certainly not all; the holdco still has hundreds of campaigns in market through traditional rails). And the AdCP protocol is still early enough in standardization that the next twelve months will determine whether the rest of the industry, the other holdcos, the publishers, the IAB Tech Lab, converges on it or fragments into competing protocols.
What we have, then, is the largest holdco on earth saying out loud that direct-publisher agentic buying is strategy, with live spend behind the claim. That’s a different artifact than the keynote-stage conjecture that’s filled NewFronts and Cannes for two years.
The Trade Desk, Magnite, and PubMatic all report Q1 results in the next two weeks. Their analyst calls will tell you more about how serious the disintermediation read should be than any further Omnicom press release will. Watch the language for “PMP,” “direct,” “curated,” “supply-path optimization,” “agentic.” The specific frequency with which independent DSP and SSP CEOs invoke those words now is the inverse of how confident they are about their position three years out. Wren’s word is “toll.” Their word will tell you whether they intend to argue with him.
