UPDATE: Sunday, Jan. 17 (2:30 p.m. ET) – Netflix has kept its viewership numbers under lock and key, and when NBC exec Alan Wurtzel presented info on how many people were watching the streaming service’s shows (based on a sampling of Netflix users), it was only a matter of time before Netflix addressed it.

That happened this morning during Netflix’s portion of the TV Critics Association press tour in Pasadena, with Netflix chief content officer Ted Sarando’s heaping scorn upon NBC’s presentation.

“So there’s a couple of mysteries in play for me. One is why would NBC use their lunchtime [press conference] to talk about our ratings,” Sarandos quipped. “Maybe ’cause it’s more fun to talk [about] than NBC’s ratings. The second is, the whole methodology and the measurement and the data itself doesn’t reflect any sense of reality of anything that we keep track of. That could be because 18-49 year old viewing is so insignificant to us. I can’t even tell you how many 18-49 members we have. We don’t track them. It’s an advertising-driven demographic that means nothing to us. I don’t know why anybody would be spending so much energy and time and given what I believe is remarkably inaccurate data … I don’t understand the methodology of it. The outputs don’t reflect any reality that we track.”

In fact, Sarandos suggested the focus on viewership is part of an old paradigm that’s falling away. “There’s a very natural inclination to say, relative to this show, this [other] show’s a failure,” he said. “That puts a lot of pressure on the talent that we don’t want … if we turn it into a weekly arms race by doing box scores for every [Nielsen-issued ratings report, we’re] going to have the same result as it’s had on [traditional] television, which I think has been remarkably negative in terms of the quality of shows.”

We know that lots of viewers are streaming shows on Netflix, but how many? Those numbers are kept secret by the streaming giant, which has never publicly released its viewership information.

During a Wednesday presentation during NBC’s portion of the TV Critics Association press tour, however,  NBC Universal president of research and media development Alan Wurtzel explained tracking viewership in today’s new television, and presented ratings numbers indicating how many people actually watched Netflix’s most buzzed-about series.

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While Wurtzel didn’t have the actual Netflix numbers, according to The Hollywood Reporter, the data is statistically valid, coming from a sample of 15,000 users covering the months of September, October, November and December.

Based on these stats, Wurtzel demonsrated that Netflix’s most-watched shows during that time period was Jessica Jones, which attracted 4.8 million viewers in the target demographic of 18-49.

Close behind was Aziz Ansari’s Master of None with 3.9 million viewers in the same age range, while Narcos drew 3.2 million viewers.

Narcos may fall short in the top three as the study started a few days after the shows reveal, and Wurtzel admitted that the bulk of viewership of Netflix originals takes place within the first few days of their release.

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“It’s a very different business model,”; Wurtzel said of how Netflix differs from network television. “Their business model is to make you write a cheque next month. So not every program on Netflix is a broad appeal program… I don’t believe there’s enough stuff on Netflix that is broad enough and is consistent enough to affect us in a meaningful way on a regular basis.”;