1 Billion Songs and God knows how many videos,( that will be sold in a year from now). I think video will give songs a good run for their money before it's over. After all, Apple has not even released their video iPod, that's coming soon. They've taken over the video market with just an iPod that handles video.
As to who's buying a billion songs? I'd say about everyone except the Apple bashers out there that pride themselves in only finding negatives to say about the company.... now we don't know anyone like that do we? :-)