Penn Badgley stars in “You,” which moved from Lifetime to Netflix. (Washington Post Illustration/Lifetime)

This past fall, Ashley Thomas of Los Angeles got quickly hooked on a new Lifetime drama titled “You,” starring Penn Badgley of “Gossip Girl” as a psychotic stalker who becomes obsessed with a woman who visits his bookstore. Thomas urged her friends, especially those who were “Gossip Girl” fans, to check it out, but they mostly ignored her suggestion.

“They shrugged it off because it was on Lifetime,” Thomas, 23, explained.

Fast-forward two months: Netflix, which acquired the rights to “You” early last year, launched it on the streaming service the day after Christmas. Suddenly, social media blew up as viewers obsessed over the twisted, addicting series. Thomas’s friends started asking her: Had she heard of this great new Netflix show called “You”? It starred the guy from “Gossip Girl.” She might like it! After the fourth recommendation, Thomas fired off a tweet.

“I would really appreciate it if people stopped thinking that You is a new show now that it’s repackaged as a Netflix Original. You didn’t discover it. It was on Lifetime for 10 weeks,” she wrote. “Stop telling me to watch a show I already watched weeks ago.”

Thomas is far from the only one annoyed by the recent popularity of “You” and its now-common description as a “Netflix show.” Twitter is currently filled with similar missives, from TV critics (The Washington Post’s Hank Stuever: “Also depressing: reviewing it, thoughtfully and with advice to watch it back in September, only to be ‘informed’ by your readers of its existence once it goes to Netflix”) to viewers (“The people watching You on Netflix are FAKE FANS to those of us that watched it on Lifetime!!!!!!!”)

In an email to The Post, Badgley said he wasn’t surprised by the surge in attention from new Netflix viewers.

“We’re grateful to Lifetime for being the gateway to getting the show made. We wouldn’t have been able to make the show without them, as far as I can tell,” Badgley said. “There is no sense of bewilderment that the show had one reaction while it was on Lifetime and another when it went to Netflix. The difference in viewership is obvious, and it’s indicative of so many different things, not the least of which is the way young people consume media.”

But to some in the industry, it’s more than just another example of the behemoth streaming platform boosting the profile of a TV show, such as the spike in popularity of the CW’s “Riverdale” or a new generation discovering NBC’s “Friends.” This is perhaps the most stark example yet of the iron grip Netflix has on younger viewers, and a fascinating case study for where the increasingly fractured future of TV is headed.

“The more I think about it, the more I think ‘You’ flailing on Lifetime and being treated by the viewing public as a Netflix original is going to be remembered as a major turning point in what will shortly be a contraction of the TV industry,” tweeted Variety TV critic Daniel D’Addario.

For one thing, it shows basic cable channels that rely on scripted content are in for a uniquely tough road ahead. They don’t offer easy binge-watching like streaming services; they don’t have news or sports like broadcast networks; they can’t be R-rated like premium channels; and they don’t have the budget to cast, say, Julia Roberts (Amazon Prime’s “Homecoming”) or Emma Stone (Netflix’s “Maniac”). Plus, as former network executive Tom Nunan said, even if they could afford a major movie star, who knows whether their audience would watch?

“In this marketplace, how do channels like these survive? That’s the chill that goes down the necks of these guys,” said Nunan, former president of UPN and a professor at the UCLA School of Theater, Film and Television. “It isn’t ‘Netflix gets to buy whatever they want,’ which is a daily truth they have to swallow, but, ‘How are we going to survive?’ That’s the harder truth they’re facing.”

It becomes a difficult question: Whose fault is it if a show fails? Does a series such as “You” flop on cable simply because of audience bias against traditional cable networks? Or are those networks not accurately catering to their audience?

On paper, “You” seemed like the perfect series for Lifetime, best known for its “women in peril” original movies. Based on the popular book series by Caroline Kepnes, the TV show follows Joe (Badgley) as he sinks deeper into his obsession with a graduate student, Beck (Elizabeth Lail), and resorts to horrifying measures to control her life. The show, which frequently provides tongue-in-cheek commentary on 20-something Brooklynite culture, also offers nightmarish lessons about social media.

So, for a network that built its brand on movies about terrifying things that could happen to women (“Stalked by My Doctor”) and dangers of the Internet (“Cyber Seduction: His Secret Life”), “You” seemed like a natural fit, updated for the modern dating era.

“The subject matter, the studio, the showrunner, the cast — I honestly believe Lifetime did everything right putting together that show,” Nunan said. “For whatever reason, Lifetime’s platform as a cable channel just didn’t seem to tolerate the way this was executed.”

Lifetime took a chance, hoping that millennials (the most likely audience) would find the show. But because many young viewers don’t have cable TV access or think of it as an option, they missed it. The ratings weren’t terrible: The show averaged about 1.1 million viewers a week, including DVR and delayed viewing. Still, even though Lifetime executives loved the show and optioned a second season before the first debuted, the numbers simply weren’t high enough to justify continuing the expensive series on their network.

“You” wrapped on Lifetime in November. From the beginning, Netflix had the second-run U.S. rights and first-run global rights of the show, which is produced by Warner Horizon Scripted Television. When Lifetime passed on a second season, Netflix decided to take over the series completely and ordered Season 2 as an official Netflix original.

A few weeks later, it proved to be a wise decision: Season 1 started streaming and sparked an Internet frenzy. Mentions on social media skyrocketed. The stars gained hundreds of thousands of new Instagram followers. Badgley seemed amused at the renewed attention as he started tweeting back to fans who found his deranged character inexplicably charming. (Note: Gross.) On Thursday, Netflix executives announced in a shareholder letter that they estimate more than 40 million member households will watch “You” in its first four weeks on the streaming service. (As usual, there’s no way to verify these numbers, because Netflix isn’t monitored by a third party.)

In the end, it wasn’t a fair fight. Netflix has the ability to cater to exactly what its subscribers want — to splash recommendations across the home screen as a suggestion to viewers looking for something similar to “Gossip Girl.” That tactic won out over Lifetime’s traditional platform. As writer Richard Rushfield said, “You have to look at the reality of who the audience is, and consider a show that gets buzz on Netflix might not cause a ripple here.”

“What Netflix has shown the ability to do, beyond what almost anyone else can do right now, is create a sensation,” said Rushfield, editor of entertainment industry newsletter the Ankler. “I’m not sure how much of it is them managing and consciously creating that, or sensations just arising out of their shows.”

It really is hard to tell: Recently, Sandra Bullock’s “Bird Box” became a viral hit, despite being mediocre. Marie Kondo has urged people to declutter for years, but once her show hit Netflix, thrift stores across the country witnessed a spike in donations.

Of course, it’s all part of Netflix’s two-decade-long effort to get to know everything about its users and target shows such as “You” directly to them to keep them renewing their subscriptions.

According to Gina Keating, author of “Netflixed: The Epic Battle for America’s Eyeballs,” the company watches you watch television — when you stream, what time you stream, where you are, what kind of device, what shows you watch. Basically, whatever patterns they can discern from your viewing habits.

“It’s creepy in a way but also endearing,” Keating said. “They figure out a way to straddle that line between creepy and feeling like they know you.”