Hm. I think it boils down to the fact that I think fandom is as much what one does as it is the community. Especially since so much of fandom happens on the internet, fans have to make specific decisions about what sort of fan they are. And what is recognizable as "fan-activity' is not always, or-- even when you're performing the same activity, because of the choices being made about where you perform that activity, how you perform it and who you perform it with, your fannishness is subject to scrutiny or judgment.