> "You like [music type]? Here are more bands/artists of [music type]."
So far I've found the opposite. Pandora has exposed me to music that I never would have sought out on my own. In fact I can think of several artists that I would have judged by their cover, so to speak, and never given a chance even if I had stumbled on them on my own, instead of coming to awareness mid-song that "I don't know what this is, but I kind of like it."
My wife teases me about this a little bit when she finds me listening to music that she says isn't 'me' or doesn't seem like something I'd like. She's right, but I guess Pandora knows my tastes better than she does (and better than I do, to be fair.)