Well, I think lots of people have different motivations for writing fanfic, and a lot of it is for a fun that doesn't involve a grueling process of editing or getting it out on paper. But the cool thing about people like you, from what I've read of your writing, is that you're good enough for even your off the cuff stuff to be good. And I have a story by you saved up to read and I'm excited! *bounces*

Also, I'm very used to writing for an audience and I think by keeping one in mind it stops you being too self-indulgent.

Great point. If you're writing just to please people you'll never succeed, but if you're writing to please yourself and using audience as like a tool--a sort of backboard--a lot of good can come from that, which is one of the main things I wanted to address with this post.