Last.fm is a UK-based Internet radio and music community website, founded in 2002. It claims over 30 million active users based in more than 200 countriesOn 30 May 2007, CBS Interactive acquired Last.fm for £140m ($280m USD).
Using a music recommender system called "Audioscrobbler", Last.fm builds a detailed profile of each user's musical taste by recording details of all the songs the user listens to, either on the streamed radio stations, the user's computer or some portable music devices. This information is transferred to Last.fm's database ("scrobbled") via a plugin installed into the user's music player. The profile data is then displayed on the user's profile page. The site offers numerous social networking features and can recommend and play artists similar to the user's favourites.
Users can create custom radio stations and playlists from any of the audio tracks in Last.fm's music library, and are able to listen to some individual tracks on demand, or download tracks if the rights holder has previously authorised it.