Nielsen’s ongoing efforts to measure viewing of video content across screens and devices–which have hit a few bumps as the stakes have gotten higher for the TV business–are taking a significant step forward with the offering of a syndicated solution for viewing on subscription video on demand.

Specifically, that means tracking shows as they play on Netflix. Customers at launch include NBCUniversal, Disney-ABC, A+E Networks, Lionsgate, Warner Bros. Television and three more that Nielsen did not name. The new SVOD metrics will include not just ratings but data points such as reach, frequency and segmentation reporting, elements common for years in the world of linear TV. Streaming on Amazon Prime and Hulu are expected to follow in 2018, but for now the expansion covers Netflix–and, significantly, not on mobile devices.

The news comes as networks, although eager to present flexible, tech-driven new ways for viewers to watch their programming outside of linear timeslots, are nonetheless exasperated that they are not able to monetize all of that viewing. By many measures, levels of overall TV viewing remain healthy despite cord-cutting and digital distractions, and even the sheer number of U.S. TV households has increased. Yet traditional ratings keep declining, even for once-invincible programs like NFL football games or CBS sitcoms.

Syndication is considered a crucial step in the pursuit of a universal ratings currency, something many participants in the $70 billion TV ad game have felt that Nielsen historically wasn’t able to deliver. Rather than merely catering to clients on a one-to-one, bespoke basis, the concept of syndication means that Nielsen is delivering metrics that both buyers and sellers determine to be genuine, and those numbers create a marketplace where transactions can occur. Amid the uncertainty about Nielsen’s capabilities, some networks have invested in their own measurement tools, and 21st Century Fox, Viacom and Turner (none of which was named of today’s announcement) formed a collective last spring called OpenAP designed to improve insights for audience-based ad buying.

One of the most vocal critics of Nielsen in the past has been NBCUniversal, whose participation in the new Nielsen rollout was confirmed several hours after word of the offering first started to circulate, suggesting they were late to fully commit. Last December, with Nielsen moving to roll out an expanded multi-platform ratings tool, a harshly critical letter to the company from NBCU ad-sales chief Linda Yaccarino dismissed it as “not ready” for prime time. “Some say, ‘something is better than nothing,’” Yaccarino wrote. “We disagree. Bad, inaccurate and misleading data is far worse than no data at all.”

Nielsen says its new syndicated plan captures when and how viewers engage with content in the current ecosystem, where smart TVs and devices like Roku or Apple TV enable seamless shifting between linear signals and SVOD and some MVPDs even bundle streaming services alongside traditional channels. “The significant growth of SVOD services in entertainment markets across the world has created demand from rights owners to understand the size and composition of audiences relative to other programs and platforms,” said Megan Clarken, president of watch for Nielsen. “The syndication of SVOD measurement as part of Nielsen’s Total Audience offerings represents a big step forward in terms of moving closer to transparency within the SVOD marketplace.”

Nielsen began measuring streaming content in 2014 via an opt-in service. While some marginal players have tried using audio signals or other technological means of measuring SVOD viewing, Nielsen says its plan uniquely matches data from SVOD with demographic and household characteristic information from its national TV panel in order to refine and authenticate the numbers.

Programmers now routinely promote “live-plus-three” ratings or sometimes even “live-plus-seven” or higher timespans in order to reflect delayed viewing. Now, participating ones will now have a more comprehensive view, following the full lifecycle of a program from live to time-shifted viewing to set-top-box video on-demand and now SVOD.

Conversely, as SVOD-originated programs re-enter the traditional television ecosystem (as some shows have started to do), an established track record of their audience profiles will already exist. That information will introduce hard data into what Nielsen describes as “previously a significant and expanding blind spot of consumer behavior.”