I went to BurgerKing the other day and was given a token to allow me to download one song from MyCokeMusic.Com. The website itself is not to bad but what is all this Windows Media Audio (WMA) file rubbish? Apparently mycokemusic and all other legal download sites in the UK are using WMA files instead of MP3 because MP3 does not have very effective digital media rights (DRM) protection. What this means is that the recording industry can slap a sticker on the file which will only let it be played on one machine and other nasty tricks. This is an attempt to stop people sharing music files using peer-to-peer (p2p) Gnutella-like software. Anyway, these articles about mycokemusic and wippit explain everything much more clearly.
One thing though... WMA files won't play on Apple iPods!!!