Facebook has just made it easier for you to listen to your favorite artist without really ever leaving Facebook. More importantly, Facebook just also made it easier to discover new artists in a flash, which in turns makes you more likely to "like" them, or perhaps click on over to their shop and buy some merch.
Basically what I'm saying is that Facebook's new "Listen" button is great for both artists and users alike. Folks like Apple and profile apps like ReverbNation? Not so much.
Now live on musicians' pages is the new "Listen" button, positioned right next to the "like" button at the top right of their Timeline. Clicking on the Listen button will automatically open up your most-used streaming music app - whether that be Spotify, Rdio, or MOG. If you've yet to connect any of those apps to your Facebook profile, you'll be prompted to set one up (most likely Spotify).
Your app will open up an there you go. You're now listening to songs from that particular artist with very minimal effort. Let's say you love the band's sound - just look how close you are to those "like" and "shop" buttons!
It just keeps getting better for apps like Spotify. If you've spent any time on Facebook, you have probably been inundated with news feed and ticker posts about how this friend or that friend is rocking out to some artist on Spotify (or some other service). Back in January, Facebook also launched a sort of music sharing feature that allows people to listen with a friend, at the same time that they're listening to a song.
So, you're browsing your news feed and you see that your good friend just "liked" Local Natives. So you head on over to their Facebook page and click on the giant Listen button up top. You think they sound great and "like" them too. Now you've just discovered your new favorite band without ever leaving Facebook - which is of course the plan all along.