4 ms·

Google music does it all the time.

• myko 12y ago
  This is opt-in though isn't it? When I signed up for Google Music it asked me what types of music I'm interested in and if it should auto-add similar music to my library.
  • wldcordeiro 12y ago
    It doesn't even add them to your library, it shows them on your main page as recommendations that you can add to the library.