“Friends” — which last aired on broadcast TV 14 years ago — was the most binge-watched television show of 2018 thanks to the full run being on Netflix, according to a new study.

The sitcom about twentysomething New Yorkers nabbed the highest share of binge sessions over the course of the year, according to TV Time, based on its analysis of the behavior of 12 million registered users worldwide of its app for tracking, commenting on and voting for television shows.

The enduring popularity of “Friends” (corroborated by other third-party research) clearly motivated Netflix to re-license the show from Warner Bros. Television: It was set to roll off Netflix at the end of 2018, and after a social-media uproar the streamer announced a new deal to keep “Friends” on the service through at least another year. Netflix reportedly agreed to pay around $100 million to keep all 10 seasons following Rachel, Monica, Ross, Chandler, Joey and Phoebe available to customers in the U.S. and Canada.

No. 2 on TV Time’s ranking was ABC’s long-running primetime drama “Grey’s Anatomy,” whose past seasons are available on Netflix. That was followed by Netflix’s controversial teen-suicide show “13 Reasons Why”; Spanish-language series “La Casa de Papel” (“Money Heist”), which premiered on Spain’s Antena 3 in 2017 before it was picked up by Netflix; and The CW’s “Riverdale” (the first two seasons of which also are on Netflix). TV Time defines a binge session as one in which a user watches at least four episodes of a show within a 24-hour period. For the annual report, bingeing patterns were calculated from Jan. 1-Dec. 13, 2018.

But take these rankings with a really big grain of salt.

For starters, the binge-watching data aggregated by TV Time is self-reported by users of the free app — it’s not a passive measurement service that tracks actual viewing behavior. In addition, the company says the app’s base of 12 million users skews young, comprising primarily people 18-34. TV Time’s business model is geared around selling data and analytics to networks, streaming providers, studios and others.

Another important point: Popular shows on traditional broadcast and cable channels are likely to be underrepresented in TV Time’s binge-viewing data, because episodes of current seasons are released weekly. Fans of, say, “Game of Thrones” would be far less likely to stack up four or more episodes to watch in one sitting than, for example, people who were eagerly anticipating season 2 of “13 Reasons Why.” Note that CBS’s “Big Bang Theory,” one of the top ratings-getters on primetime television, came in No. 9 on the TV Time list.

That said, here are TV Time’s rankings, for what they’re worth:

Top 10 Binge-Watched Shows of 2018

Rank Show Network/Service Share of Binge-Watching 1. “Friends” Netflix 2.36% 2. “Grey’s Anatomy” ABC/Netflix/Hulu 2.07% 3. “13 Reasons Why” Netflix 1.69% 4. “La Casa de Papel” (“Money Heist”) Netflix 1.69% 5. “Riverdale” CW/Netflix 1.68% 6. “Brooklyn Nine-Nine” Fox/NBC/Hulu 1.40% 7. “The 100” CW/Netflix 1.25% 8. “Orange Is the New Black” Netflix 1.19% 9. “The Big Bang Theory” CBS 1.16% 10. “Pretty Little Liars” Freeform/Netflix 1.06%

Source: TV Time