Shazam, an app that identifies songs just by listening to them, is giving special treatment to users who pay for streaming music services such as Rdio.
After tagging a song in Shazam's iOS app, Rdio subscribers can listen to the entire track instead of being limited to short preview. To turn on this feature, just tap the arrow next to the play button, select "Listen with Rdio" and enter your login credentials. A little Rdio icon will then appear next to the play button, indicating that you can play the full track.
The app also includes a button for quickly adding the song to any existing Rdio playlist. Just tap the "+" icon at the top-right corner, and you'll see a list of playlists to choose from (including a "My Shazam Playlist" that the app creates automatically).
This feature won't be limited to Rdio subscribers for long. Shazam said additional services will be supported in "the coming weeks." Presumably, you'll be able to just hit the arrow next to the play button, and select your service of choice from a drop-down list.
Shazam had already included buttons for playing a tagged song in Rdio or Spotify, but these buttons simply linked to their respective apps. Shazam, which intersperses its free app with ads, would prefer that you stick around and check out other features, such as artist bios, discographies, lyrics and concert ticket purchases. Being able to quickly drop a song into an Rdio playlist may encourage you to stay in the app, and having full playback functionality could be useful if you want to quickly listen to a few songs you tagged previously.
Although these features are iOS-only for now, they'll be available on Android in the next few days. There's no word on support for the Windows Phone version of the app.