Subscription music services are counting on the new Facebook Music initiative announced earlier this week to attract millions of Facebook users into free trials of their services.  At the f8, Facebook’s annual developers’ conference, CEO Mark Zuckerberg introduced the new Open Graph platform which will allow you to see which songs and tv shows, for example, your friends are enjoying.First up in a few weeks will be music-based apps music-based apps which will appear as a music dashboard on Facebook’s new user experience, Timeline. The new platform will allow you to register, with just a few clicks, for services like music subscription service Spotify when you want to listen to a song your friend posted in his Facebook feed.”When you click to hear a song, it creates a new user for us,”Axel Dauchez, CEO of Deezer, a Europe-based service that’s part of the new Facebook Music initiative (but not available in the USA), told USA TODAY. “The Facebook integration will create tens of millions of trials for my service, and my goal is to convert them to paid subscribers.”This same Facebook strategy using Open Graph could work for almost any subscription content providers, so look for Facebook to be a key player in marketing subscription sites.