Streaming music services are very convenient to search and save favorite songs. I was previously using Pandora, but was dissatisfied with it. While one may enter a few songs (create a station) to activate the algorithms to discover similar songs, one can not save these new discoveries and return to them. Enter Spotify!
This service allows you to save new favorites, which is a nice and useful feature. There is also the similar feature of Pandora where similar songs can be played for your enjoyment, but you can save these. Unlike Pandora, you can search for songs by title or artist. Notifications are periodically sent when new material is available from artists in saved playlists.
Overall a good and free service.