Nielsen and Roku are working together to measure video advertising delivered via Roku’s 10 million players and smart-TV devices — a development the parties tout as the first connected-TV platform to offer audience guarantees that exist in traditional television.

About half of the 250 most-watched Roku channels, including CBS All Access, already deliver ads, but in selling that inventory publishers have had to extrapolate audience demographics for ad impressions.

Now, Roku channel partners will be able to measure audience according to Nielsen’s standard demo breakdowns. Nielsen will collect usage data from Roku devices (stripped of personally identifying info) and then will use its National People Meter television panel to assign audiences.

Initially, Nielsen and Roku will enable over-the-top advertising measurement through Nielsen Digital Ad Ratings, with a test slated to begin this summer. “We believe all TV will be streamed, and with it all TV advertising,” said Scott Rosenberg, Roku’s VP of advertising. “Nielsen solves a couple of really hard problems – like how do you know those 100,000 impressions were served against an 18-34 demo?”

The key difference with the new approach is that it incorporates census-level data from each Roku device, instead of relying solely on panel-based measurement, which would not produce a big enough sample size to estimate demos, said Kelly Abcarian, senior VP of product leadership who is responsible for Nielsen’s TV ratings strategy. “The benefit to the publisher is, Nielsen working with Roku means you have it in the platform,” she said.

The Nielsen-Roku deal is separate from the measurement firm’s effort to gauge viewing of certain content on subscription VOD services including Netflix and Amazon Prime. That’s also slated to begin a test phase this year, but it will track SVOD viewing only on TVs (not computers or mobile devices) and will let content owners view data only for their own titles on the services.

Roku will include the Nielsen tracking capabilities as part of the Roku Ad Framework, a new toolkit for channel partners that includes Innovid’s iRoll interactive ad-serving software and a new Roku ID for advertisers directly into the devices’ operating system.

“Roku’s move to bring advanced advertising measurement and delivery technologies to its platform is an important step in the progression of digital video distribution,” Marc DeBevoise, CBS Interactive exec VP and g.m. of entertainment, sports and news, said in a statement.

In 2014, Roku users streamed more than 3 billion hours of video. (For the sake of comparison, Netflix said subscribers worldwide consumed 10 billion hours in the first quarter of 2015 alone.)