bop.fm believes you should be able to listen and share any song from any music service. Their website brings together many other music services into one place. So even if a friend uses a different music service, sharing and listening is still possible at bop.fm.
Beats Music has become available on bop.fm joining Rdio, Spotify, YouTube, and SoundCloud. Share a bop.fm music link with someone that might not subscribe to any other service, bop.fm will likely find the song and still allow a listen.