As Roku kicks the tires on NBC’s canceled “Zoey’s Extraordinary Playlist,” it’s the latest streamer to potentially play hero for TV fans yearning to see their favorite bubble shows saved. It’s a common refrain: Revive a canceled series with a vocal fan base, and then capitalize on the attention that comes with acquiring a show with that rabid following.

Netflix has done it several times, with AMC’s “The Killing,” A&E’s “Longmire,” ABC’s “Designated Survivor,” Lifetime’s “You” and Fox’s “Lucifer.” Hulu early on revived “The Mindy Project,” also from Fox. And Amazon gave a second life to Syfy’s “The Expanse” and now, Pop TV’s “Flack.” (Then there’s Yahoo! Screen, which launched — and folded — with the final season of NBC’s “Community.”)

But shifting a broadcast or cable show to streaming is complicated. License fees, episodic orders and budgets are all different, and that makes renegotiating deals difficult. That’s partly why the “Zoey’s” revival at Roku hasn’t yet been announced, while plans to revive CBS’ “Clarice” on Paramount Plus fell apart. In streaming, there’s limited back end, if any at all, which means higher upfront “cost-plus” license fees to cover everything. (Compare that with the deficit finance model in broadcast, where license fees are lower but studios make up for it in the aftermarket.)

Now, networks are shifting shows to their sister streamers when it makes sense. NBC’s “A.P. Bio” has moved to Peacock, while CBS has slid “SEAL Team” and “Evil” over to Paramount Plus. But it’s not a slam-dunk: NBC couldn’t make a “Zoey’s” move to Peacock work from an economic sense, and that’s what similarly stalled “Clarice” from heading to Paramount Plus from CBS.

Here, for example, is how the transition works for “SEAL Team”: The plan calls for a 14-episode guarantee for Season 5, with four episodes set to air on CBS and at least 10 more to run on Paramount Plus.

According to sources, the negotiations to continue the show on streaming included a provision stating that should “SEAL Team” get renewed for a sixth season, only 10 episodes would be guaranteed, not the traditional 13 a broadcast series would get. Granted, Paramount Plus could order more episodes, but as it stands, the main cast is looking at a pay reduction to the tune of at least 23% should the 10-episode order hold.

Revivals aren’t easy. IMDb TV, for example, just broke hearts by opting not to revive ABC’s “Rebel” and “For Life.”