EFF: The Customer Is Always Wrong: A User's Guide to DRM in Online Music
The EFF has written a nice plain language write-up regarding the various online music services. Lets you know what rights your giving up. Right now I occasionally buy songs from the iTunes store. This is mostly because it’s a decent audio format (mpeg4) and the DRM is easily stripped. If either of these change then I’ll likely stop buying.
EFF: The Customer Is Always Wrong: A User’s Guide to DRM in Online Music