Just off the top of my head, I'd rank writing fiction forms, from most to least freedom:
- Online role-playing
- Writing and never sharing it with anyone
- Writing to independently publish
- Writing for publication
You can in theory only make money off those last two, though there can be some overlap. Of course some NaNoWriMos are made into salable fiction, and if you write fanfiction of public domain characters, you can sell it (and sometimes make some good money!).
Anyway. Just rambling, mostly. Blogging has more freedom and less freedom than all of those...not liking the deadlines of writing a few times a week quite so much. :)