Fans of the Netflix series GLOW have been patiently (for the most part), awaiting word on whether the women’s professional wrestling comedy will be returning for a third season. Season two racked up an impressive 10 Emmy nods after it hit the service in June, and some fans expected a swift renewal announcement. But the show’s creators were mum at a Television Critics Association panel over the weekend on whether the show would officially continue.

Netflix doesn’t just choose whether to renew a show on the size of its audience, or even the critical acclaim—it matters how committed the fans are. One of the biggest deciding factors is whether viewers who started watching the season stick with it until the end. It gives Netflix a sense of whether the show will be able to draw enough viewers for subsequent seasons to justify the sometimes substantial costs Netflix’s originals cost to create.

Audiences who bailed partway through Everything Sucks!, a buzzy, coming-of-age dramedy on Netflix, contributed to the cancellation after one season. It wasn’t enough that fans raved about the show, according to Cindy Holland, Netflix’s vice president of original programming, at another Television Critics Association event on Sunday.

“We were seeing a much low [sic] completion rate of the whole season,” Holland said, according to Deadline. “We realized that it is very unlikely that we would be able to grow the audience, move a whole new audience through the show, and have a large enough audience to justify a season two.”

The sci-fi drama Sense8, which had a passionate and vocal fanbase, was also cancelled by Netflix last year because its audience wasn’t strong enough to sustain the show—one of the most expensive on Netflix at the time. That suggests that the share of viewers who complete each season need to be sizable enough to “support the economics of the show,” as chief content officer Ted Sarandos said last year. (Sense8 did briefly return for a finale special to appease diehard fans who were aggrieved by its cancellation.)

The company says it’s taking more shots on original programming, which inevitably means more cancellations as it figures out what works and what doesn’t for its audience.

Passionate fanbases have, however, given Netflix the confidence to pick up series that were cancelled by other networks, like Lucifer, which Netflix recently rescued for a fourth season after it was dropped by Fox, as Polygon pointed out. The fantasy drama had small but relatively steady ratings that ranged from 2.5 to 3.5 million live-and same-day viewers for much of its third season. Fans took to Twitter to beg Netflix to save the show, and it worked. It’s found a new home on Netflix, like Longmire, Arrested Development, and Degrassi before it, all of which have been revived by the streaming service.

Netflix and other streaming-video services like Amazon Prime Video don’t release viewership numbers, so it’s not always easy to gauge how a show is performing from the outside, apart from word of mouth and critical acclaim. Netflix, of course, has tons of data on viewership habits that it keeps to itself—not even sharing the numbers with series creators.

Third-party measurement firms like Nielsen, which track viewership on major streaming-video subscriptions, offer a glimpse.

For the new season of GLOW, about 1.3 million people in the US were watching the first episode within the first three days it was released, during an average minute of the show, Nielsen reported. (It measures how many people watch during an average minute of the content, much like it tracks TV.) About 395,000 people, meanwhile, watched the final episode of that season.

The immediate drop off isn’t necessarily cause for concern. The Emmy recognition in mid-July could’ve boosted completion rates. And Netflix has said its viewers are more likely to take their time watching smart comedies like GLOW, than binge them in a single sitting. But it could also be why Netflix is holding back on that renewal announcement.

For anyone worried, the single biggest thing you can do to keep GLOW alive, apart from tweeting incessantly at Netflix, is finish the latest season in full.