Much like it did with Rdio last month, Shazam has partnered with Spotify to offer full-song playback.
That means Shazam users who also have the Spotify app installed on their iOS or Android device can have Shazam identify a song then tap a dropdown menu to have the Spotify app open and play the full track. Assuming that it's present in Spotify's millions-strong library, of course.
Shazam has similar arrangements with Deezer and Rdio in place already. You can add the functionality by updating your Shazam app to the latest version – we've tried it on Android this morning and it's already up and running.