On the surface, Last.fm and Pandora seem redundant. Both recommend new music based on your current favorites, and allow you to influence their suggestions by approving or disapproving of each song as it plays. But while Pandora suggests songs based on their underlying musical characteristics, Last.fm relies on guilt by association. The formula is right out of the Amazon playbook: “Fans of band x also listen to band y. You like band x, so you will probably like band y.” To illustrate the difference between the two approaches, Ben Gibbard is the lead singer for both the indie rock Death Cab for Cutie and the electronic The Postal Service. While Pandora would likely never recommend one to fans of the other, Last.fm deems them the closest match.

Last.fm has over 21 million active users in more than 200 countries, which makes their recommendation engine quite powerful. Download the software to connect your media player to their database (i.e. enable “scrobbling”). Most desktop media players are supported, along with the iPhone and Google’s Android OS. Obviously, your plays on the site are also tracked.