For the third time in less than two years, Nielsen is about to roll out a significant change to its media measurement, something that will once again have huge impacts across sports media.
Following its introduction of expanded out-of-home tabulation early last year and the September 2025 rollout of Big Data + Panel process, Nielsen is readying a widespread adoption of a new co-viewing measurement methodology.
The new system is aimed at providing greater clarity on group viewing patterns and follows a pilot program conducted early this year. On the heels of that effort, Nielsen is now preparing the expanded co-viewing to be part of official audience measurements, known within the media business as “currency,” as soon as September and the arrival of the 2026–27 television season.
“This is obviously complex stuff, but our goal is still very simple: we want to be as accurate as possible, and this is the next iteration of Big Data,” Nielsen head of global sports Seth Ladetsky tells Front Office Sports.
Here are four key questions surrounding the latest big change from Nielsen that is now on the horizon:
What Exactly Is Co-Viewing?
This is the measurement of group viewing within a single household at the same time. It’s already been part of Nielsen’s methodology, but is now being expanded to include members of its viewership panel wearing proprietary smartwatch-type devices.
Those devices, not previously part of Nielsen’s co-viewing modeling, passively capture audio codes from TV broadcasts and are designed to provide greater accuracy to this part of the audience measurement.
On a conceptual level, this technological enhancement is similar to last year’s addition of data from set-top boxes and smart TVs, which is now core to the Big Data + Panel process.
Why Does It Matter?
As has long been the case, viewership data for any programming, and particularly live sports, is a crucial factor in setting advertising rates. That advertising, in turn, is the key way that networks recoup the billions of dollars in rights fees paid to license that content. As a result, more reliable—and higher—viewership data generally leads to greater ad revenue.
As the entire media business continues to go through accelerating disruption and audiences splinter further, the power of live sports stands out even more, in turn making this content a focal point for the broader measurement changes.
In 2025, 96 of the 100 most-watched programs on U.S. television involved live sports, tying a record. A similar number is expected this year, thanks in part to major events such as the FIFA men’s World Cup and a 2026 NFL regular season that carries big expectations.
“Sports is the most complex thing we do, and the NFL is the most complex within that,” Nielsen SVP Brian Fuhrer tells FOS. “It obviously has the biggest audiences, the highest profile, and a lot goes on in the background to get this right. But the core principles of what we do remain the same throughout.”
What Are the Early Expanded Co-Viewing Results?
The pilot program from earlier this year yielded an average 4.19% viewership lift for a series of marquee events in February, including Super Bowl LX, the opening and closing ceremonies of the 2026 Winter Olympics, the gold medal game in men’s hockey from those Olympics in Italy, the Daytona 500, and the State of the Union Address.
Had that expanded co-viewing measurement previously been part of the official audience measurements—it won’t be until at least the new television season—Super Bowl LX would have set a new record for the largest audience in U.S. television history.
This initial boost is less than the 10% to 15% increases and the bevy of new viewership records, generally seen in sports during the 10 months of Big Data + Panel so far. But given the scale involved in top live sports, even a 4% hike in viewership can result in billion-dollar swings in rights fee values over time.
Nielsen, however, has been insistent that each process change, including this latest one with co-viewing, is not about delivering audience increases. Rather, the goal is to use technology to better reflect the content consumption that’s already happening.
“These are things that just make so much sense,” Fuhrer said. “It takes a lot of work, and there are a lot of things still happening [around this], but we really want to bring this to market because it will help our clients make more sense of what’s happening out there.”
With the continued influx of Nielsen methodology changes, though, it will now be late 2027, at the earliest, before year-over-year audience comparisons can be made on a truly apples-to-apples basis.
How Have Leagues and Networks Reacted?
Anybody in the business of television programming, or selling advertising around it, obviously has a vested interest in seeing the full extent of their audiences reflected in the listed numbers. Like with the prior two methodology shifts, there is scrutiny around seeing that the co-viewing rollout happens correctly.
In particular, the NFL has consistently had issues with Nielsen on this particular topic—including before the adoption of Big Data + Panel. The league has long felt that its audiences, though by far the largest in all of U.S. television, were still being undercounted amid the hefty group watching inherent to NFL fandom.
“I have to give Nielsen credit. We’ve pushed them really hard about this,” NFL chief data and analytics officer Paul Ballew told FOS in February. “It’s been an issue for us for some time now, and has been frustrating. But they’ve listened and come up with ideas to address the issue.”
With the co-viewing program now done, league sources tell FOS that their sentiments are largely the same. While the NFL remains encouraged by Nielsen’s continued diligence in this area, the co-viewing situation is still a work in progress.
NASCAR, meanwhile, has been in a somewhat similar position and has delayed its full adoption of the existing Big Data + Panel methodology until the expanded co-viewing arrives as well.
Even before the adoption of the expanded co-viewing, Fox has been paying particularly close attention to this metric during the ongoing World Cup. Initial group-stage matches on the network averaged 2.2 viewers per household. That’s close to the 2.4-person co-viewing average for the Super Bowl that has been considered a “gold standard” for the industry, even as the NFL has questioned that latter figure.
That group viewing during the soccer tournament will likely serve as something of a baseline to compare against once the new Nielsen methodology is in place, particularly during big upcoming sports events.
“We love to see the signs that the World Cup is bringing fans together,” Fox Sports president of insights and analytics Mike Mulvihill said in a social-media post.
