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Ad Tech Briefing: One last row before back to school

This Ad Tech Briefing covers the latest in ad tech and platforms for Digiday+ members and is distributed over email every Tuesday at 10 a.m. ET. More from the series →

The role of Transaction ID (TID) in programmatic advertising has become one of the most contentious topics in recent weeks, as buyers, sellers and technology intermediaries debate its implications for transparency, control and revenue. 

The latest flashpoint bubbled to the surface last week when Prebid quietly issued a change that rendered TID non-unique across exchanges, effectively undermining its primary purpose of helping buyers detect duplicate bid requests. The change was initially rolled out with little public notice, but concerns about governance and influence in open-source standards were soon raised.

On August 27, Ari Paparo, CEO of Marketecture Media, flagged the issue on X, drawing broader attention to the development, which sparked an impassioned debate soon after.

Why it matters

Related Insights

TID, part of the Prebid and OpenRTB standards, is a unique identifier that can tie multiple bid requests for the same impression back to a single auction. For buyers, particularly demand-side platforms such as The Trade Desk, it is a tool to cut through the noise of excessive request duplication and route spend more efficiently toward high-quality publishers.

However, for publishers and some supply-side platforms, broad adoption introduces risk: exposing duplication could depress yields, shift leverage toward buyers, and diminish already limited control over auction dynamics.

The implications extend beyond individual revenue lines. For advertisers, cleaner auctions promise efficiency and reduced waste. For publishers, however, there is fear that transparency will accelerate commoditization and tilt power further toward dominant DSPs. The Prebid adjustment deepened this unease, removing the ability for publishers to choose whether or not to implement TID and forcing the debate into a governance crisis over open-source technical standards.

Publisher pushback

Much of the recent debate has unfolded publicly on both LinkedIn and X, with one of the most prominent responses from Paul Bannister of Raptive, who warned that TID could erode publishers’ last line of data control.

In his example, a publisher running three exchanges could designate a deal ID with a $20 floor in one, but allow open-market pricing in the others. With TID, a DSP could simply ignore the deal ID auction and bid on the cheaper alternatives, effectively bypassing publisher intent. Bannister concluded, “Publishers have given up basically all data control at this point, and this would be the final nail in the coffin.”

This perspective resonated widely, highlighting publisher skepticism that TID, while positioned as a transparency tool, might also facilitate buy-side exploitation of data signals and weaken deal-based monetization.

Online discourse

Additionally, last week, the August 29 edition of the Marketecture Podcast featured a debate between Jounce Media’s Chris Kane and The Trade Desk’s Mike O’Sullivan, further crystallizing opposing viewpoints on the merits of TID.

  • Chris Kane, Jounce Media: Publishers worry that exposing duplication will reduce revenue and give DSPs greater leverage, while also raising concerns about buy-side dominance and potential data leakage.
  • Mike O’Sullivan, Sincera, by The Trade Desk: TID reduces wasteful auction duplication, rewards higher-quality publishers, and helps keep the open web competitive with walled gardens by creating cleaner, more efficient auctions.

Prebid vs. Tech Lab?

Adding weight to the discussion, Anthony Katsur, CEO of the IAB Tech Lab, weighed in on LinkedIn, stating that Prebid’s change violates OpenRTB consistency and risks fragmenting standards. He urged industry stakeholders to engage in a formal process to ensure transparency without destabilizing the ecosystem.

Meanwhile, Gareth Glaser used his widely read Substack, Gareth Hates Ad Tech, to bluntly ask, “Why can’t we all just get along?” His commentary reflects the widespread weariness with recurring transparency debates in ad tech, suggesting that while TID may appear technical, its real impact lies in entrenched mistrust between buyers and sellers.

The Transaction ID debate illustrates how technical debates are, in reality, often ciphers for a power struggle in programmatic advertising. For buyers, TID represents an opportunity to streamline spend and reward transparency. For publishers, it is seen as yet another mechanism for buyers to assert control and erode margins.

With Prebid’s decision undermining TID’s effectiveness and industry leaders like the IAB Tech Lab calling for clarity, the issue now stands at a crossroads. Whether the ecosystem can coalesce around a standard that balances transparency with publisher autonomy remains unresolved.

But as the intensity of the online discourse shows, the implications for efficiency, fairness and trust across digital advertising are anything but trivial.

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