I don't think Fandom is a club, though there are fanboys of anything that would swear otherwise. You don't have to prove anything to be a fan. You don't have to cosplay, speak klingon, memorize the specs of the ships, or even like every series. You're a fan because you like the show, and that's it.
If Trekkie means that I have to memorize lots of crap, dress up like a Romulan and speak klingon, I may have possibly been a fan for about 2 weeks in junior high school. Of course I can't be a "true anime fan" because I can't read japanese and watch the english version. I must not be a Boston Legal fan because I don't know what brand of shoe Denny Crane wears. When did "true fan" get to be so elitist?
I'll be welcoming, but I hope I won't be the only one.