Originally Posted By: andy
No, Napster's model was just straight forward p2p exchange of ripped tracks. The "you can download the mp3s if you have the CD" was someone else's model Can't remember who it was, I think there was more than one service with the same model.

That would be the defunct mp3.com's "Beam-It" technology. Their server issued a challenge to the client to compute the hash of some unpredictable range of the CD. If the client could answer enough of these hashes, then they would add the MP3s to your account on the server right away. MP3.com was sued by the RIAA and had to can the service.