This is absofrigginlutely brilliant...
-- Laurie Duncan, TUAW
I couldn't agree more.
During the Grammy Awards, Apple created and distributed 500 custom iTunes cards for the charity song "Across the Universe" and sent the cards to major radio outlets around the U.S.
The cards featured artists who had performed the song (including Steve-o's iPod poster boy, Bono) and they quickly became collectibles.
Then, at SXSW, Apple expanded the program to the performing bands and finally, the interest has been so intense that they've opened it up to the overall market.
What better way to sample a band's music (and iTMS) than to distribute a collectible card, good for one song?