MP3.com has been a piece on the board of Internet music game for quite some time now. After being acquired by Vivendi Universal, the My.MP3.com service was used as a platform for PressPlay music store. It was the My.MP3.com service that run MP3.com into trouble in the first place, since RIAA decided to sue MP3.com over the Beam-IT service at My.MP3.com. Using Beam-IT MP3.com users were able to access their CDs online without actually encoding them to MP3 format and transferring them to the service.
After Roxio acquired the assets of both Napster and Pressplay, along with MP3.com back end technology, there was little interest for Vivendi to maintain the service. In November, 2003 Vivendi sold MP3.com domain name to CNET Networks. On December 2nd, 2003 MP3.com ceased to exist.
Source: The Register