It’s about time! Now you can go back and buy the rest of an iTunes album at a discount if you previously bought one song. Just go to the iTunes Music Store and in the upper right choose “Complete My Album”.
This is great mainly for several reasons: If you bought one song off an album that had 12 songs on it (for $9.99) you can now get the other 11 for $9.00 instead of having to buy the whole album (it looks like it’s full credit). Also, if you bought one song off an album and some of the songs were “album only” purchases you now have the option to get rest since you’re actually buying the whole album. For a 10 song album, it really doesn’t make a difference. Not all artists are doing this and you only have six months to get your missing albums, but it’s a nice option if you regretted not getting it in the first place. FYI, they did grandfather in all the old albums you bought more than six months ago (so you can still get the missing ones).
I’m not sure if this will help if you bought a pre-release single since I haven’t bought that many. I’m pretty sure a few of the songs on the list are ones I’ve (purchased) for free, but I could be mistaken. And I know there are a few that I didn’t purchase off the album they are showing, I must have bought off some other album or special purchase mix that iTunes offered (iTunes Originals or something).