At what point does a musical act go mainstream? It's impossible to be sure. A metric of placing bands on a "sell out" spectrum from say Yo La Tengo to Black Eyed Peas, sadly, does not exist. Perhaps someday some geek will develop a BCS-type system determined by the number of myspace friends a band has, how many Dave Matthews Band fan club members have heard one of their songs, gross ticket sales, venues they play, etc. But not yet, so whether a particular group or individual has achieved the level of ubiquity to have some stake in the popular consciousness is still a mystery. Also, I think these hypothetical sell-out rankings would have to occur outside the Internet. Because cult status is what the web is all about, fanaticism disguises magnitude, ardent supporters voice their opinions the loudest. Which is all "a way" of saying that I don't think Girl Talk is mainstream, despite their/his online pervasiveness when a new album is released.
Suppose that is what I was thinking about when I went to see Girl Talk at the Electric Factory in Philadelphia some time ago. We went what I like to call "Sinclair Style" which means showing up at a venue without tickets and running around like a maniac seeking good, legitimate tickets and maybe a half-drank mini-keg of Heineken. The thing to remember about "Sinclair Style" is that it is best attempted in the presence of Sinclair or a Sinclair-type figure, which means you yourself do not have to do much running around because he, being Sinclair, will be doing so himself and you can just sit in a bar around the corner and reflect on the obscenely sexual lies he told you on the drive into Philadelphia, in leiu of talking because of loudness of which the the bar is blaring Katy Perry and other undoubtedly mainstream acts. Or you could think about Katy Perry's boobs.
Anyway, yes, the show itself was fun. Like going to a club where they play Girl Talk and balloons fall from the ceiling. This video is a terrible but fair representation.