Their selection is generally limited to independent artists and classical music. Really popular music you want? It probably won't be there- you'll have to go to another service that charges more than a quarter a track for it. But I'm finding benefit in limitation- by wandering around their archives and listening to the thirty-second samples, I'm finding music I didn't know existed, and enjoying it greatly.
Case in point: I had an urge to hear a particular track of classical music, which I didn't have available, so I checked eMusic. I did find what I was looking for- but then I found two variants of it as well.
Did you know that, in addition to the classical way of playing it, Flight of the Bumblebee can be played on guitar, or electric guitar and full drum set? That's three more of my monthly downloads down.
If any of y'all want to try out the site, by the way, I'd appreciate it if you'd ask me to send you a referral e-mail. This shameless promotion was brought to you by a "get 50 free MP3s for getting a friend to subscribe" deal. Actually, I really do like the site and want to share it around- but of course I'd like to be listed on a referral...
But whee, that track is just fun.