Michael Robertson intended to start this service when he founded mp3.com but RIAA shut it down and the domain was bought out by cnet.com. mp3tunes.com is Robertson’s vision clarified. It’s not really intended to share mp3 files, it’s more like a remote mp3 storage. mp3tunes.com is basically a service where you send your mp3’s to a remote server and you can access it anywhere through any computer with an internet connection.
I have yet to try it but it seems like a cool service. It’s not only compatible with mp3 files but also MP4, M4A, M4P, AAC, WMA, OGG, AIF, AIFF and MIDI files. It is said to work with iTunes. I think you stream your music. Storage for the free service is unclear but if you pay for the $39.95 a year premium service, you get unlimited storage so you can put all your music in the mp3 locker (good way to back up your music collection). Another difference between the free and premium is the streaming bitrate. It’s 56k for the free and 192k for the premium. You can buy music from this site as well and the interface is pretty much the same UI as iTunes music store.