http://www.411mania.com/movies/columns/271270

4) NBC's relationship with Community is a lot like the relationship it had with Scrubs, which eventually went to ABC for a couple lackluster final seasons. Both are really quirky shows that fall out of NBC's wheelhouse. They don't know what to do with Community. Do to that, they don't devote a lot of time to promoting or caring for the show. They switch time slots, they pull it from the schedule. The thinking seems to be that Community is a really niche show with a small fan base and that fan base will go with it no matter what, but the series doesn't have potential to grow the fan base. The ratings are low, but critical praise and the strong, but small, fan base has kept it around. The show has been retooled for its fourth season to start in February. Showrunner Dan Harmon has left along with some other writers, directors and producers. Chevy Chase also parted ways with the show, but after most of the fourth season was filmed. He'll only be missing from two episodes.

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