apparently some of the biggest artists which include madonna linkin park radiohead are unhappy at the apple Itunes legal download system as it charges 99$ a cd and has proved very sucessful
but some groups now require albums to be bundled instead of releasing singles and they ( the artists ) are concerned that if they allow singles to be released it could cause compaines undercutting each other and cause a slumb in album sales
more in the link
http://www.billboard.com/bb/daily/ar...ent_id=1919550