NBC thinks they’ve figured out how many viewers are watching Netflix shows.

The streaming company is notoriously secretive about revealing the viewership of series like Daredevil, House of Cards, and Narcos. The company’s lack of ratings transparency frustrates traditional networks like NBC who are rated by Nielsen and have seen their share of live viewerships shrink dramatically in recent years — with the media reporting every weekly decline — while streaming companies rise in popularity, rack up awards and buzz, all without having to reveal how many viewers are actually watching their shows.

In a presentation to reporters at the Television Critics Association’s press tour in Pasadena on Wednesday, NBC’s longtime analytics guru Alan Wurtzel presented Netflix ratings as estimated by technology company Symphony, which measures TV viewership among its sample group using “audio content recognition technology” — software loaded on to users’ phones that tracks viewership by capturing the soundtrack of the programs they watch (which is a bit terrifying in and of itself).

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According to this data, measuring September through December, Marvel’s Jessica Jones averaged 4.8 million viewers among adults 18-49, the drug kingpin thriller Narcos had 3.2 young adult viewers and new comedy Master of None had 3.9 million. None of these titles is Netflix’s most popular show, however (in a rare bit of insight, Netflix has previously noted its biggest show is Orange is the New Black — which drops in the summer, outside of this study’s sample period).

Also, he pointed out that Amazon’s Nazi fantasy Man in the High Castle (which Amazon says was their most popular launch ever) had 2.1 million viewers in the demo.