Ad Tech Briefing: The Open Internet’s factions spar, as Big Tech players are in a dead heat for gold

• Prebid responded to intense buy-side criticism by updating its open-source framework to give publishers a choice between global or supply-side platform-specific Transaction IDs when enabling the signal (see above), ultimately softening its earlier stance.
• Separately, AWS scaled its proprietary ad ecosystems into cloud-fueled, AI-driven warfare, with many interpreting it as a response to GCP making overtures to ad tech clients – apparently, both claim such players as home turf. 

Technical change = political uproar

Prebid.org, the open-source consortium responsible for much of the internet’s header-bidding infrastructure, quietly altered how Transaction IDs (TIDs) are generated in its 10.9 Prebid update this August. The seemingly minor tweak unleashed a months-long storm that has since engulfed the industry’s buy- and sell-sides, even the IAB Tech Lab.

Buyers such as The Trade Desk saw fragmentation of the TID signal as a threat to supply-path optimization efforts — i.e., efficiencies vital to diverting ad budgets away from Walled Gardens. For some in the industry, it was a referendum on who gets to define transparency in programmatic trading.

For, without a consistent identifier, DSPs can’t tell whether multiple bid requests stem from the same impression — forcing them to pay for redundant bids and eroding trust in the open exchange — exactly the problem raised with Digiday earlier this year regarding “request duplication.”

However, to counter this argument, Prebid’s publisher committee argued that the new logic gave websites the ability to limit data leakage between exchanges and protect dwindling yield, a precious commodity in the era of AI overviews. 

As Garrett McGrath, Magnite’s svp of product and a Prebid board member, later explained to Digiday after last week’s update, “It wasn’t about breaking transparency — it was about giving publishers optionality.”

The Trade Desk fires back

If Prebid’s move symbolized publisher autonomy, The Trade Desk’s response embodied the self-determination efforts of the industry’s buy-side, with a series of launches that effectively “forked” Prebid earlier this month with the launch of OpenAds.  

Effectively, this is a forked version of the Prebid framework designed to restore global TIDs, or embed what The Trade Desk CEO Jeff Green described as “fair-auction accountability.” He also positioned this move as a cooperative layer that publishers can run alongside Prebid – he maintained this in a charged-onstage session at this year’s Prebid Summit – and said that maintaining deduplication and verification signals keeps money flowing to the open internet. 

However, the dual releases underscore a growing reality: the Open Internet’s shared infrastructure is splintering into competing rulebooks. “It’s not just a debate about identifiers,” noted one source familiar with the development, who declined to be named (such are the tensions involved with this affair). “It’s about whether the buy-side trusts the sell-side enough to keep transacting in open RTB at all.”

Prebid notes how only about 1% of publishers had even upgraded to Prebid 10.9, yet the controversy revealed “just how fragile trust is in real-time bidding.” 

As the debate first bubbled to the surface in August, voices within IAB Tech Lab were quick to weigh in, maintaining Prebid’s August release “materially non-compliant” with the OpenRTB specification and warned that open-source code shouldn’t unilaterally redefine industry standards. That public rebuke exposed a long-simmering fault line: the Tech Lab writes the protocols, but Prebid implements code across thousands of publishers, with many interpreting the formation of the latter in 2017 as a bid to counter the dominance of Big Tech within the IAB. 

Compromises 

One source, who was formerly active within Prebid, and also asked not to be named, said the group’s tone “was unnecessarily defensive. Although the source acknowledged the upside, adding “Any time you give publishers more choice and transparency, that’s a good outcome — even if the process was messy.”

McGrath framed Prebid’s October 23 clarification wasn’t a rollback, adding, “We’re just giving publishers options.” Instead, characterizing the update as a middleground, allowing publishers to toggle between global and SSP-specific TIDs. 

While the open-web factions trade GitHub commits and LinkedIn posts, Amazon and Google are playing a different game entirely — one measured not in lines of code but in terabytes of latency and machine-learning throughput.

As Joel Meyer, svp at OpenX, explained in a recent briefing with Digiday, AWS’ RTB Fabric and Google Cloud Platform’s AI stack are turning ad auctions into cloud-native workflows, with such direct integrations yielding significant reductions in operating costs for ad tech companies. “Cloud infrastructure is where the real arms race is happening,” he added. “AWS is abstracting RTB complexity; Google is embedding ad tech inside its AI services.

That’s the next-level competition, with the rest of the open web – everyone from ad tech companies to publishers – fighting for the crumbs from the big table, hoping to make up any reduction in fees with operational efficiencies.

What we’ve heard

“AI-slop at the end of the day is MFA. I think we, as an industry, need to come together and have a better definition – as tough as it is, with something that’s as subjective as this – I think we all know AI-slop when we see it.”  

– Speaking at this month’s Prebid Summit, Eric Hochberger, CEO of Mediavine, a topic he opined on extensively in a recent Reddit AMA. 

Numbers to know

• $2.36 billion: The amount sought by litigants in a recent Northern California lawsuit against Google, citing its privacy policies 
• 55%: The Trade Desk’s annual stock price decline, one that was accelerated after reports that Amazon was intensifying competition with it  
• 3.2%: The days-later increase in Omnicom’s stock price after it reported better-than-expected revenues for Q3 – $4 billion, representing 2.6% annual growth  
• 2,500: The official attendance figures for last week’s Masters of Marketing conference, hosted by the Association of National Advertisers. 

What we’ve covered

AWS’ RTB Fabric marks a new front in the battle between Amazon and Google

Amazon and Google’s battle for strategic dominance now has a new front: the cloud – i.e., the very infrastructure of digital advertising – with sources interpreting RTB Fabric as a bid to counter GCP’s efforts to win ad tech contracts. 

Google’s AdX unit has begun striking deals with media agencies

Google Ad Manager’s ad exchange, AdX, may be in the dock as part of its antitrust travails, but that has stopped its staffers from approaching media buyers with renewed vigour, offering to cut bespoke deals for the first time, according to Digiday sources.

What we’re reading

Google’s great flattening has hit managers in its ad unit

Management jobs at Google – once the most enviable of roles in the industry – are increasingly going the way of the dodo as its executive suite embraces AI, according to Business Insider’s Hugh Langley, citing a memo penned by vp Jon Nicoletti. The latest changes are impacting its Google Customer Solutions division, taking effect in January, with the result likely to infuriate customers further, given the notorious difficulty in actually speaking to employees there. 

Equativ files lawsuit against Google in pursuit of more open and competitive digital advertising markets 

Equativ, the ad tech company born out of the union of Sharethrough and Smart, has joined the number of sell-side companies suing Google over allegations made in its ad tech antitrust trial four, joining Magnite, OpenX, and PubMatic, after its October 13 filing. 

Apple and Google face enforced changes over U.K. mobile phone dominance

The UK’s Competition and Markets Authority designated Google and Apple with “strategic market status,” requiring stricter oversight of their mobile ecosystems. The regulator found both hold entrenched power over operating systems, app stores, and browsers, creating potential bottlenecks for UK businesses and consumers reliant on their platforms.

OpenAI inches toward seeing ChatGPT regulated under EU digital rulebook

ChatGPT is poised to become the first standalone AI service regulated under the EU’s Digital Services Act after surpassing 120 million EU users — nearly triple the DSA’s 45 million threshold. The European Commission and Ireland’s Media Commission will finalize its designation and supervisory fee in the coming weeks.