Many of Netflix’s most popular shows are owned by companies that plan to compete with Netflix. Which means many of those shows may vanish from the streaming service in the next few years.

So if you like watching “The Office,” “Grey’s Anatomy” or “Gossip Girl” on Netflix, you should enjoy them while you can. More than half of the 50 most popular shows on Netflix are owned by companies planning to launch their own streaming services — Disney (and its to-be-acquired Fox), NBCUniversal* and WarnerMedia — according to data from analytics firm Jumpshot. Jumpshot measures online views of Netflix TV shows and movies by tracking the web pages its panel of users visit. The top 50 Netflix shows account for 42 percent of all Netflix views, according to Jumpshot.

But just because a Netflix competitor has a popular show on Netflix doesn’t mean they’ll take it away from Netflix: They could also charge Netflix a lot of money for it. Last month, for instance, Netflix shelled out $100 million to WarnerMedia for exclusive rights through 2019 to “Friends,” a show that first aired a quarter of a century ago.

That deal makes more sense when you learn that “Friends” is the second-most-watched show on all of Netflix, with about 4 percent of total views this year, according to Jumpshot. The most-watched show is NBCU-owned “The Office” (U.S. version), which accounts for about 7 percent of all views.

Note that Netflix itself owns a number of the most-popular shows, according to Jumpshot, including “Orange Is the New Black” and “BoJack Horseman.”

Jumpshot generates its data by looking at web browser activity on an anonymized global panel of 100 million web devices from which it sees billions of online actions each day. For this data set, every time a U.S.-based device went to a Netflix web page to play a TV episode or movie, that counts as a view.

Netflix has said in the past that the overwhelming majority of its views come from people watching on connected TVs, and Jumpshot’s data doesn’t measure that behavior. But it’s reasonable to assume that people who watch Netflix via browsers and people who watch on Rokus or Xboxes tend to watch the same stuff. Netflix declined to comment.

* NBCUniversal is a minority investor in Vox Media, which owns Recode.