There are some similarities. Last.fm recommends music that people might like, based on music that they have expressed a preference for. watchmi recommends TV programs that people might like based on TV programs that they have expressed a preference for. However, the underlying technology is very different. Last.fm is centralized, and recommendations are based on a dataset that is built from many people's data. watchmi is decentralized, and only uses preferences that are local to the Windows Media Center installation. This makes it more personal.