In a report out today, the Video Advertising Bureau alleges significant discrepancies in Nielsen’s data-backed audience measurement methodology that serves as a basis for buying and selling TV ads. Nielsen has strenuously denied the allegations, calling the report “seriously flawed and manipulated,” a spokesperson said in a statement shared with Marketing Dive.
The VAB claims that Nielsen’s Big Data + Panel currency is “unstable, unpredictable and decimating demographics,” per information shared with Marketing Dive. Accredited by the Media Rating Council in January, Big Data + Panel unites the firm’s historic panel measurement approach with data from cable, satellite set-top boxes and smart TVs from across 45 million households.
“It turns out the begrudging Upfront use of Nielsen’s not-really-ready Big Data trading currency has already gone to worst-case-scenario on early returns,” said Sean Cunningham, president and CEO of VAB, in a press release.
The VAB’s report is based on an analysis comparing the differences between Big Data + Panel and Panel-Only audiences drawn from four weeks of data from 33 networks. It found between 45% and 58% of total hours analyzed had more than a 20% audience variance between the two currencies, resulting in what it describes as a “deep instability” in the viewership assessment of major trading demographic groups for viewers aged 25-54, 18-49 and 18-34.
The report also spotlights issues with how NFL game audiences have been measured. NFL games accounted for 48 of the 50 top-rated programs during the reporting period. VAB claims the audience should be stable: the programming is essentially the same, week to week, and the audience is large and loyal. But instead of stability, the VAB found high and irrational variability in NFL audiences, whether analyzing hour-by-hour, network-by-network or cumulatively across networks. Between 16% to 40% of hours with NFL games had double-digit audience variances — which could mean the difference of hundreds of thousands of viewers in key demos during higher-rated games.
If the VAB’s report is correct, this would be particularly troublesome for advertisers that have flocked to football as the last bastion of large, live audience engagement. However, Nielsen claims that the VAB pulled data for live sports without accounting for the same games airing in different time zones across the U.S. Elsewhere, Nielsen claims the VAB made other unclear or incorrect assumptions about its data, at times “comparing apples to oranges.”
“From what we have seen, the VAB incorrectly pulled our data and the bureau does not know how to do a proper ratings analysis,” the Nielsen spokesperson said. “The VAB is wasting the time and money of its members.”
Herculean efforts
Overall, a “significant percentage” of hours analyzed by the VAB had over a 50% variance between Big Data + Panel audiences and Panel-Only audiences among key demographic groups, and one in ten hours had “severe” variances on the 18-34 demographic, per the report. During a press briefing discussing the report, Cunningham attributed the problems to issues with Nielsen’s Household Demographic Assessment Model.
“This HDAM thing that we complained about until we were blue in the face and did so for the last 18 months is exactly what has thrown all these demographics off the rails. It's going to take some kind of Herculean effort to correct this. This is, right now, a broken demographic model,” Cunningham said during the briefing.
Nielsen in a July product note said that HDAM was “not driving significant differences in demographics between panel only and big data + panel services.”
The VAB is a TV advertising trade body that counts among its members publishers including heavyweights Disney, NBCUniversal and Warner Bros. Discovery, along with scores of media organizations and companies in the measurement and adtech space.
The organization has been a frequent critic of Nielsen and called out the measurement giant around underreporting of audiences during the early pandemic period. The Media Rating Council would go on to strip Nielsen of its National TV ratings accreditation, which Nielsen regained in 2023.
Nielsen received accreditation for its Big Data + Panel offering from the MRC in January 2025, ahead of the crucial upfront period. Since then, Nielsen has worked to re-entrench itself as the leader in measurement, securing deals with publishers, agencies and ad tech players. Just last week, Nielsen expanded its relationship with Horizon Media in a deal that included a partnership around Big Data + Panel.
“Nielsen continues to provide best-in-class, person-level data that helps us bring richer, data-driven solutions to our clients,” said Michele Donati, executive vice president and chief of futures at Horizon Media, in a press release last week about the news. “Our first-to-market integration, together with TransUnion, marks a pivotal step in building the next generation of advanced audience planning and measurement that drives business outcomes for our brands.”
