Smile, a track previously only available on the 'The Complete U2 Digital Boxed Set', is a special bonus addition to the new album when you pre-order on iTunes UK.
If you're interested - and it's a hidden gem of a song from the 'Rare and Unreleased' category of the Boxed Set - you need to pre-order 'U218 Singles' over the weekend.
More
here.
