exfm works by pulling music off of blogs, Tumblr, Bandcamp, Soundcloud and a variety of other sources. You can also utilize the Chrome, Firefox and Safari extensions if you want exfm to keep track of all the music you come across in your daily searching. It will automatically add any MP3s you come across to your queue.
You don't have to use that feature, though; you can also just browse through the already massive library of music sorted into exfm. It has all kinds of ways to discover new things, including an album of the week and the ability to follow plenty of people with more time than you to dig through music blogs. The top tiered will get notched into the tastemakers section, which is an easy way to pop in and see what the kids are listening to these days.
What makes exfm more interesting than every other services is the social element, and one of the reasons that's a great feature is because you don't really have to take part in it if you don't want to. You can fly blind by simply searching through the explore option, hitting up the trending option or browsing through the "latest loved" section to see what random people have been recommending.
For the most part, exfm only tracks legal tracks placed on blogs, although a few things will come up now and again that aren't legit. Either way, exfm is the easiest to use music discovery engine we've used. It's certainly more geared towards those looking for something fresh and new, but between the label playlists and a few top tastemakers, you'll be able to find (and of course share) tons of new music in just a few minutes.