As movie sequels dominate the box office with more than 30 slated this year alone, including Iron Man 3, Star Trek 2 and Hangover 3, television too is increasingly relying on expanding TV franchises. In a symbolic move, as the last CSI spinoff, CSI: NY, bowed out this season, a record three new spinoff series are joining the broadcast schedule for next season: The Once Upon A Time spinoff Once Upon A Time In Wonderland, The Vampire Diaries offshoot The Originals on the CW, and Chicago Fire‘s Chicago PD on NBC. They will join returning spinoffs NCIS: LA and Law & Order: SVU. Of the four spinoff projects that were in consideration for next season, only one, CBS’ NCIS: Red, didn’t get a series pickup. “Sometimes they work and sometimes they don’t,” CBS entertainment president Nina Tassler said last week about the decision. “Protecting (the NCIS franchise) was really important.” She indicated that the network is open to trying the spinoff again. Indeed, I hear there is talk about revisiting NCIS: Red with a new cast.

Once a staple in comedy with All In The Family, The Mary Tyler Moore Show, The Cosby Show, Cheers and Family Guy among the slew of hit series to launch spinoffs, offshoots are primarily limited to drama these days. NBC tried to break the trend with The Office this season, but the proposed spinoff didn’t take off. And, eager to capitalize on their successful series, the networks tend to spin them off earlier then ever. Chicago Fire had been on the air less than a season when NBC plotted the Chicago PD spinoff. Once Upon A Time is launching a spinoff only two seasons into its run. In the past, the networks normally waited at least four seasons for a series to establish itself before launching an offshoot. The major exception was the CSI franchise whose expansion was done methodically, adding a new series every two years.

Spinoffs are not as prevalent on cable where they’re mostly used as an attempt to extend the life of a hit series after it ends, like Battlestar Galacticas offshoot Caprica on Syfy, The Closer‘s Major Crimes on TNT and the Breaking Bad spinoff in the works at AMC.