It added another 1.93mn US subscribers in the last quarter alone, and expects to hit around 50mn in the States by the time winter is over. Netflix is a TV success story.

But the growing popularity of a subscription-driven, ad-free service that keeps its viewing data under lock and key is also bad news for advertisers.

Turner chief research officer Howard Shimmel wants to understand the Netflix audience a whole lot better than he does today, because he sees a problem.

“They’re in 45m homes roughly in the United States,” Shimmel tells Beet.TV in this video interview. “The average user uses them for two hours a day. That would mean they are taking a pretty significant chunk of minutes out of the market.

“We may not have long sight to 10% to 15% of viewing that goes on every night. You don’t want to have that much blindspot. We need to know how they’re doing.”

Netflix, famously, keeps that viewing data to itself, and skillfully uses it to customise its commissioning and procurement patterns for more new shows.

Right now, Shimmel may simply want to understand what his audience is doing when its not watching his TV networks like CNN. After all, Netflix doesn’t compete for advertising.

But TV analysis firm Ampere’s Richard Broughton, a year ago, told Beet.TV that Netflix could make $270mn per quarter from selling pre-roll ads or $2bn a quarter from a broadcast-style model – both of which would nevertheless lead to varying degrees of churn from upset customers.

And the issue doesn’t just apply to Netflix. “It extends down to platforms like YouTube,” Shimmel adds.