First off, as the name implies, they've got great jazz tunes in the background.
Secondly, and actually, this may be the FIRST thing you notice, there are rows of bras hanging from the ceiling as you enter. If you want a free T-shirt, wear a bra you don't mind giving away to add to the collection. The idea of this really offended me at first and maybe it still sort of does, but it's all just fun and games and the staff here is really friendly. It is a great place to hangout.