Spotify is a great way to listen to a whole album and decide whether it's worth buying, and it's awesome for helping you find new artists to like (kind of like related videos on YouTube). I've gotten into maybe 20 new artists just by trying out suggestions and checking out Related Artists. Unless you have a premium account, it's worth it just to avoid the annoying commercials. But, if you buy it, it's yours, so you'll have it whenever, wherever, forever.