If OpenRTB isn't valuable anymore, why pay for the association that stewards it?
In the shifting terrain of programmatic advertising, two industry coalitions have emerged with competing philosophies about how media buying should evolve in an era of artificial intelligence. The Advertising Agents Organization envisions a radical dismantling of legacy infrastructure in favor of AI-native systems, while the IAB Tech Lab's Programmatic Governance Council seeks to preserve and refine the protocols that have long connected buyers and sellers across the open web. Their disagreement is not merely technical — it reflects a deeper uncertainty about whether the open web itself can survive the gravitational pull of walled gardens, and whether incremental reform or structural reinvention offers the better path forward.
- Programmatic advertising's growth is decelerating and the open web's share of display investment is projected to fall to just 18.9% by 2027, creating a burning platform beneath both camps.
- The AAO, backed by figures like Brian O'Kelley and agencies including Omnicom, is pushing a protocol called AdCP designed to let AI agents execute media buys with minimal human involvement — a direct challenge to established middlemen and infrastructure.
- The IAB Tech Lab's 40-member Programmatic Governance Council, convening biweekly with heavyweights like The Trade Desk, Amazon Ads, and WPP Media, is betting that targeted fixes to bid duplication and supply chain waste can rescue the existing ecosystem.
- A bitter 2025 dispute over Prebid's transaction ID changes exposed deep fault lines in the industry, and the AAO's subsequent alignment with Prebid's camp signaled that the peace-making effort behind the Governance Council remains fragile.
- The central unresolved question is existential: if AI agents render OpenRTB obsolete, the entire institutional purpose of stewarding that protocol collapses — and no one yet knows which vision of the future will prove correct.
Two rival visions for programmatic advertising's future are hardening into competing organizations, each backed by different players and driven by fundamentally different assumptions about what the industry needs to survive.
The Advertising Agents Organization — the AAO — positions itself as the insurgent. Built around a protocol called AdCP, it enables agencies like Omnicom and Butler/Till to deploy AI agents capable of executing media buys with minimal human intervention. Co-founded by Brian O'Kelley of Scope3 and the consultancy Ebiquity, the AAO frames its mission as a challenge to established power structures. Its first annual general meeting, scheduled for May 6, will seat a board divided equally among agencies, publishers, advertisers, and ad tech companies.
On the other side, the IAB Tech Lab launched its Programmatic Governance Council last month — a 40-member advisory body including Paramount, The Trade Desk, Hearst, Amazon Ads, and brand advertisers like Bayer and Hershey's. Meeting biweekly, the Council addresses fraud, supply chain inefficiencies, and what CEO Anthony Katsur calls the industry's 'partial coordination failure.' It stewards OpenRTB, the foundational protocol connecting demand- and supply-side platforms, and sees incremental improvement — not reinvention — as the path forward.
The philosophical gap is significant. The IAB Tech Lab camp focuses on eliminating waste like bid duplication, which Omnicom Media's Ben Hovaness calls 'arguably the single biggest unnecessary cost in the whole ecosystem.' The AAO's backers go further, questioning whether OpenRTB will even matter once AI agents dominate media buying — and whether a trade body built to steward an obsolete protocol has any future at all.
The tension has recent roots. A dispute over Prebid's transaction ID changes in August sparked an acrimonious industry debate, and an October town hall at Magnite's New York headquarters was meant to restore trust. The Governance Council grew from that effort. But when the AAO aligned with Prebid in January, collaborating on a publisher-facing AI sales tool, it signaled the divide was far from resolved.
Beneath the rivalry lies a shared anxiety. Programmatic display spending is projected to reach $203 billion this year, but annual growth is expected to slow from 17.4% in 2024 to 11% by 2027. More troubling is the open web's shrinking slice: publishers outside walled gardens captured 23.3% of programmatic display investment in 2023; by 2027, that figure is forecast to fall to 18.9%. Both organizations understand that without meaningful change, the decline will continue — they simply cannot agree on what meaningful change looks like.
Sources close to both groups suggest the competition need not be zero-sum. Multiple standards bodies have coexisted in ad tech before, and at least one AAO insider acknowledged ongoing dialogue with the IAB. But the outcome of this contest will determine whether the industry's future is built on AI-native architecture or on a reformed version of the infrastructure it already has.
Two visions for the future of programmatic advertising are crystallizing into rival camps, each backed by different industry players and animated by fundamentally different assumptions about what comes next.
The Advertising Agents Organization, or AAO, positions itself as the insurgent. It's a nonprofit trade association built around AdCP, a technical protocol that allows agencies like Omnicom and Butler/Till to develop and deploy AI agents capable of executing programmatic media buys with minimal human intervention. The group's founders—including Brian O'Kelley of Scope3 and the consultancy Ebiquity—frame their mission as a direct challenge to the industry's established power structures. Their first annual general meeting is scheduled for May 6, where members will elect a board split equally among agencies, publishers, advertisers, and ad tech companies.
But the AAO is not alone in trying to shape programmatic's future. Late last month, the IAB Tech Lab launched its Programmatic Governance Council, a 40-member advisory body that includes Paramount, The Trade Desk, Omnicom, Hearst, Dentsu, Amazon Ads, WPP Media, Yahoo, and brand advertisers like Bayer and Hershey's. The Council meets biweekly to address issues ranging from fraud to supply chain inefficiencies. Anthony Katsur, CEO of IAB Tech Lab, describes it as a neutral arbiter intended to fix what he calls the industry's "partial coordination failure."
The philosophical divide between these groups runs deeper than organizational structure. The IAB Tech Lab's approach emphasizes incremental improvement to the existing programmatic ecosystem. Its members are focused on reducing waste through better coordination—bid duplication, for instance, which Ben Hovaness, chief media officer of Omnicom Media, calls "arguably the single biggest unnecessary cost in the whole ecosystem." The Council will make recommendations but not write new standards. It stewards Open RTB, the foundational protocol that connects demand-side and supply-side platforms, and sees that infrastructure as essential to programmatic's future.
The AAO, by contrast, envisions a more radical restructuring. Its backers question whether legacy standards like Open RTB will even matter in an era when AI agents handle most media buying decisions. One anonymous AAO supporter posed the challenge bluntly: if Open RTB becomes obsolete in an agentic future, why maintain a trade association whose primary job is to steward a protocol nobody uses anymore? The AAO's approach aims to build systems that serve agentic architecture directly, potentially eliminating middlemen and established infrastructure altogether. Early tests by Omnicom, according to the company's chief technology officer Paolo Yuvienco, are designed to use AdCP to do exactly that.
The tension between these groups has roots in recent industry conflict. In August, changes to transaction IDs made by Prebid sparked an acrimonious debate that exposed fault lines among ad tech players. An October town hall meeting at Magnite's New York headquarters was meant to clear the air. The Governance Council emerged from that effort as a healing mechanism. But the AAO aligned itself with Prebid's camp in January, collaborating on a Prebid Sales Agent for publishers—a move that suggested the divide was far from healed.
Underlying both groups' urgency is a shared anxiety about programmatic's trajectory. Overall programmatic spending on digital display is projected to reach $203.04 billion by the end of this year, but growth is decelerating. EMarketer forecasts that annual growth will fall from 17.4 percent in 2024 to 11 percent by 2027. More troubling still is the shrinking share flowing to publishers on the open web. In 2023, open web publishers captured 23.3 percent of programmatic display investment. By 2027, that figure is expected to drop to just 18.9 percent as spending concentrates in walled gardens controlled by tech giants.
Hovaness articulated the stakes plainly: without action to improve efficiency and effectiveness, the decline will continue unchecked. "I don't think that would be good for our clients long term," he said. The Governance Council, in his view, is one mechanism to reverse the trend by stripping unnecessary costs from the system. The AAO's backers would argue that incremental fixes won't be enough—that only a fundamental reimagining of how media buying works in an AI-driven world can save the open web from irrelevance.
Despite the rhetorical sparring, sources suggest the groups are not necessarily locked in zero-sum competition. Multiple standards bodies have coexisted in the ad industry before. One AAO insider acknowledged active engagement with the IAB and Tech Lab, noting that both organizations share the same ultimate goal—they simply haven't settled on the best path forward. Still, the outcome of this contest will shape whether programmatic advertising consolidates around AI-native standards or whether Open RTB remains the foundational protocol for years to come.
Notable Quotes
Bid duplication is arguably the single biggest unnecessary cost in the whole ecosystem that effectively adds no value in the way that it gets abused.— Ben Hovaness, chief media officer of Omnicom Media
Unless we do something to improve the overall productivity of the ecosystem in efficiency and effectiveness terms, that decline will continue.— Ben Hovaness
The Hearth Conversation Another angle on the story
Why does it matter which group wins this argument? They're both trying to improve programmatic, right?
The difference is in what gets preserved and what gets discarded. If the IAB Tech Lab's vision prevails, you're optimizing the existing plumbing—making Open RTB work better, reducing waste in the current system. If the AAO wins, you're potentially ripping out that plumbing entirely and building something new around AI agents.
And that affects advertisers how?
Costs, mostly. The AAO argues that middlemen and legacy infrastructure add unnecessary expense. If AI agents can negotiate directly with publishers without going through all the intermediaries, prices could fall. But there's also risk—you lose the standardization that Open RTB provides, and you might fragment the market.
So the IAB Tech Lab is the conservative play?
Not conservative exactly—more evolutionary. They're saying the existing system can be fixed without burning it down. But they're also defending the protocol they manage, which is worth noting. The AAO sees that as a conflict of interest.
Is there a real chance the open web disappears?
That's what's driving both groups. Programmatic spending on the open web is already shrinking—it'll be less than 19 percent of display investment by 2027, down from 23 percent just four years ago. The walled gardens are winning. Both organizations are trying to make the open web competitive again, just with different tools.
Which approach actually works better?
Nobody knows yet. That's why they're both still talking, despite the tension. The real test will be whether Omnicom's early experiments with AI agents actually reduce costs and improve results. If they do, the AAO's vision becomes harder to ignore.