First there was Radiohead, with their last CD sold online at a fee decided by the listener. Everybody was happy about this operation: fans had the chance to choose how much the album worth, nearly every media talked about this new way to sell music and that was an incredible spot to that CD and the better adv to the tour.
After that success in the last month other artist choose to leave a preview of their work on the web. Nine Inch Nails decided to let surfers download a full 320kbps mp3 version of their last album while Coldplay decided to promote Viva La Vida or Death And All His Friends giving away the first singles Violet Hill and A Spell A Rebel Yell.
Another - and perhaps the most significant - positive opinion to this business model comes form Metallica (Up the Irons!). This is particularly important since that band with a legal battle killed Napster as a popular file sharing software.
Since nobody buys anymore a CD and on line shop aren't as remunerative as hoped the only thing to do is to change the way listeners can get songs. In such a new business model the common listener gets the music he likes for free and in a legal way. He would have picked some songs form p2p networks, so artists and majors aren't losing nothing. On the other hands the CD are sold only to true fanatics of the band. That means a full quality disk, deluxe package and, of course, crazy priced product. Who isn't a true fan listening to songs available (and to every media talking about the band) would probably want to go to to live events, the other main source of revenue for musicians.
Everyone seems to win in this business model: listeners get free songs, fanatics get a full-optional products and artists (with majors) could have the same revenue. It sounds too good to be true, where is the problem? I can't find out nothing strange nor a disadvantage, so I will wait with the hope that something would change.
Here you can pick the songs I talked about on the article. If you know other artists that let you download free music write a comment and I will update this list.