Ad Tech Briefing: Platforms’ measurement transparency moves into view

By Ronan Shields • December 9, 2025 •

Ivy Liu

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 →

In an era when the major internet platforms’ share of advertising spend looks set to increase, and no media plan is (seemingly) complete without the slightest hint of AI, there’s a growing curiosity to probe what goes on inside those black boxes among advertisers.

And away from the headline-grabbing platforms such as Google’s Performance Max, Meta’s Advantage+, or Amazon’s Performance+, growing attention is also being paid to the veracity of more established third-party measurement programs, the two most prominent of which, on YouTube and Meta, are now more than a decade old.

These programs allow a select number of third-party outfits, i.e., those officially approved by the platform and, in many cases, accredited by the Media Ratings Council, to offer advertisers greater reassurance that they are getting what they pay for in environments where accountability was historically hard to come by.

However, a long-running assumption in digital advertising is coming under scrutiny, i.e., whether brands should be paying third-party verification companies for viewability metrics inside walled garden platforms. Zefr is now openly challenging that premise — and doing so in a way that could create pressure on longstanding pricing models of the verification behemoths DoubleVerify and Integral Ad Science.

Zefr CEO Rich Raddon recently told Digiday that his company, which has viewability accreditation on YouTube and is undergoing similar processes for the internet’s other platforms, will soon offer viewability as a free metric in walled gardens, starting with TikTok, then expanding to other platforms. The push stems from what Raddon described as a widening gap between how the market believes walled garden measurement works and how it actually does.

According to Zefr, inside walled gardens, “viewability is largely a pass-through metric,” i.e., the information is passed along for free from the platforms, and there is no direct measurement on them, further claiming that its company’s planned approach will make it unique in the market.

However, it is important to note how many sources approached for comment in this article — most of whom requested anonymity due to sensitivities around dealing with some of the internet’s largest platforms — noted how this did not mean such programs were “not important, valuable and independent.”

From here, most verification providers “charge the same amount for viewability in walled gardens as for the open web, despite the minimal effort required,” according to Raddon. He further argued that this has led to unnecessary and substantial costs for advertisers. Considering such schemes have been in operation for close to a decade, advertisers could have “spent tens of millions on a pass-through metric that should never have carried a price tag in the first place.”

Digiday approached multiple parties for comment on the above claims, with DoubleVerify and IAS unable to return official comment by press time. Similarly, YouTube’s press team did not respond on record when asked about how it facilitates its verification partnership program, while a spokesperson for Meta directed Digiday to relevant help center pages.

“Today is a wake-up call for the Industry. Unlike the open web, the walled gardens have provided free viewability metrics to third-party measurement providers who, in turn, applied some logic to that data and shipped it as a premium-priced product to the Industry,” added Raddon. “By making viewability metrics free in the walled gardens, Zefr is drawing a line in the sand; the walled gardens are different than the open web.”

A long-running blind spot

Zefr’s argument lands in a marketplace that has historically examined open-web spend far more critically than walled garden spend.

“There are always questions around programmatic on the open web, but what a lot of people don’t really know is what they’re paying for within the walled gardens,” said Ravi Patel, CEO of SWYM, adding that such environments warrant regular scrutiny, especially since most marketers spend much more of their advertising budgets there, compared to the open web. “I would say there’s a certain element of complacency when it comes to understanding ad ops, and what you’re actually buying that exists today.”

Meanwhile, Joshua Koran, an ad tech expert, a vocal critic of such large platforms, further argued that the growing shift toward trusting AI-driven platforms, like Google’s Performance Max, where buyers “set their goal, push a button, and let the black box figure it out,” is a trend likely to continue.

However, he cautioned that independent measurement remains essential to avoid significant waste, adding that the “fix” for providing independent measurement too, i.e., third-party auditing of event-level data, not just domain-level reporting.

Koran emphasized viewability as “primarily an intermediate metric, as real-time optimization already accounts for performance.” He further voiced concerns around the large platforms’ official measurement programs, such as YouTube or Meta, noting “without access to the event-level data, third-party measurement providers can only report what the platform told them, but cannot validate this independently.”

The MRC process

Raddon also noted that Zefr expects “the MRC accreditation for content-level brand safety will be announced in mid-to-late January,” forecasting that this will further reinforce the company’s position as an alternative to legacy verification firms. His comments come at a moment when the MRC is also reshaping parts of the measurement landscape. Recent guidance now distinguishes between “property and content-level accreditation,” and the industry has grappled with platforms and vendors that “only provide property-level verification, not actual content-level analysis.”

Meta’s decision to withdraw from first-party MRC brand-safety audits, instead relying on its third-party measurement providers to offer brands insights into their media buys there, adds another layer of tension.

A challenge to the market

Zefr’s chief executive further urged brands to verify what they are paying for rather than “trusting third-party providers blindly,” and it’s a message that is seemingly gaining traction with those on the buy-side of the market.

Rachel Mervis, an executive with extensive experience in dealing with ad tech as a brand-side marketer, especially verification companies, explained to Digiday some of the data transparency concerns that many advertisers have around such programs, adding that while many platforms host platforms to hear marketers’ concerns (as do leading verification providers), concerns persist. “I recall there were limitations that were frustrating,” she said, “because we wanted to see certain components or drill down further… I recall the components [of the measurement programs] being broad and finite.”

Whether the industry absorbs this shift quickly — or whether legacy players push back with counter-framing — remains to be seen. But Raddon believes this moment represents a necessary reset: “The walled gardens are different than the open web,” and brands, he argues, should no longer pay for metrics that originate within the platform itself.

What we’ve heard

“I heard that Omnicom let go of some clients yesterday too, if they weren’t profitable enough. But only rumors.”

—The OmnicomIPGmerger subreddit has been quite the read over this past week

Numbers to know

46%: The number of marketers who plan to increase media budgets for 2026, according to Ebiquity.

54%: The number of marketers who don’t plan inflation concerns and economic pressures is influencing decisions.

66%: The number of advertising leaders aiming for greater integration between media and creative functions, per the survey of 518 marketers.

67%: The number of marketers who plan to increase spend in online video, making it the highest growth channel for ad spend.

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