Oh, definitely. Like I said, it's a starting point, not an end-all be-all rule.

I think all fanfiction has the legally protected right to exist, to be written however the writer wants, and to be shared freely. (No matter how hard Anne McCaffrey tries to fight it.) But there are some things that you need permission from the original copyright holder to sell. In those cases, if you get that permission, it's probably an official spin-off (e.g. the various lines of Star Wars novels), and if you don't, it's probably fanfiction.