Spotify started rolling out new social networking features that add a new layer to the music streaming service. Key among the features is users’ ability to link to their Facebook accounts and follow and share music with their friends.

Users’ inbox folder holds music that has been sent to them from friends. Sending music is easy: just right-click and select from a list of contacts under “Send To > Spotify People” to send a song or playlist to a friend. The same options are available in the left margins next to the artist and title of current song.

Sharing via Facebook or Twitter is just as easy. You can right click and choose “Send To > Facebook” or “Send To > Twitter” in the same manner as sending a song or playlist.

On Facebook, your message goes out with an artist image with a Spotify logo. “Don’t have Spotify?” asks the text under your message. “Sign up for unlimited music with Spotify premium at”

Spotify now has a feed that tracks the music shared by your friends on Facebook. If a friend subscribes to another friend’s playlist – which requires only the click of a “subscribe” button – the event is broadcast in that person’s Facebook feed. A different friend can click on the link provided in that Facebook message to open the playlist in the Spotify application.

The most visible music service will be the one that is most actively shared via social networks. That social sharing can leverage the network effects that make Spotify more valuable as more people become users. Those who want to share more privately can take advantage of Spotify’s simple sharing features. Either way, linking Spotify and Facebook accounts helps bring out the potential in a service that has to live up to a lot of expectations.