Instant, Simple, and Free.

The montra behind the new music service, Spotify. Only recently introduced to the United States, have quickly proven to be one of the easiest and powerful music services. The question is why? What makes Spotify different from the thousands of other services out there?

For one, it’s free. Who doesn’t love free these days? Sure, Pandora and Last.fm are free, but Spotify isn’t a custom radio service; its a full online music library. Sharing with friends is another easy feature. You can either tie your account to Facebook, or use your Facebook account as your Spotify login. Search and click, and you’re listening and sharing.

The music selection is very vast, but some of your favorites aren’t on there. After running a few searches of some popular artists, we found most of who we were looking for, but still missing some big names. Given they are a new service, they are still building their library.

The interface is extremely simple. Similar to iTunes, anyone can recognize, learn and pick it up. It can also detect what you’re listening to in other programs to share on Facebook and build a Spotify playlist. If you are currently using Last.fm, Spotify will even scrobble what you’re listening to, onto your Last.fm account.

The catch? Ads. Every few songs, there are ads. A small hindrance, but every free service does it, and understandably so. This is not the only way they pay the bills, though. If you want to listen on a mobile device, you have to become a premium subscriber. The benefits are sizable, though, for having to pay. Ads disappear and you have access virtual anywhere to everything on Spotify.

Bottom Line: Get it. You can find new music, listen to as much of your favorites, and share with friends for the price of a few ads. Rather than buying