Summer is crunch time for TV executives looking to set their prime time lineups before the September schedule reveal. And things are even more hectic this year as scripted series die on the vine. The problem, it’s becoming clear, is that C3, the metric by which advertisers judge a show’s reach based on TV, DVR, and VOD play in a three day window, is showing cracks in the TV business model.

As AdAge reports, 27 scripted broadcast television shows have already completed their runs this season. That number includes the good (Parks and Recreation), the bad (Selfie) and the formerly profitable (Two and a Half Men). But, with C3 as a measuring stick, it seems clear that these shows won’t be the last to go. Shows that reach a younger audience often suffer at the hands of the metric because Nielsen doesn’t include mobile devices, and it notes when people don’t watch commercials, which is a real problem for shows aimed at younger audiences content to zip through 30-second spots.

C3 was designed to prove that TV shows still reach a broad audience, but that’s not what’s happening. C3 typically ads no more than a tenth of a ratings point to a show, which will likely need over two points to remain viable. And, for every Gotham, which was arguably saved by hefty VOD numbers, there’s a Revenge, which seems to be popular with the no-ad, tablet crowd.

What this means for executives is different than what it means for viewers. For executives, it signals the need for genuinely must-see serialized television — Game of Thrones-style shows that get spoiled for viewers who don’t watch live. That’s tough because serialized shows are a syndication nightmare (think of Seinfeld as the platonic ideal of a syndicated show). On the other hand, the C3 trend gives viewers more impetus to vote with their eyeballs. The central irony being that in order to watch their favorite shows, people are going to have to watch not their favorite show.

Ads are the price of admission for network TV shows, but it’s unclear that a generation of humans used to the price of admission being the price of admission to Netflix wanting to pay with their time.

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