I’ve never bought music from the iTunes Music Store, and I probably never will:  I ditched my iPod in favor of the Sony PlayStation Portable a while ago, so I’m locked out.  And I prefer high quality MP3 files anyway.  

For millions of people, though, the iTunes experience is just fine, although it’s always had an annoying quirk:  if you buy a couple of songs from an album for 99 cents each, and then decide to buy the entire album – most of which cost $9.99 – you end up paying for duplicates of those two songs you bought before.  

Well, that’s over. Apple now has a feature called “Complete My Album”, which lets buyers apply the cost of the separate songs toward the purchase of the full album, within 180 days of the separate purchases.  And for the next 90 days, this offer is retroactive; even if you bought Do You Feel Like We Do four years ago, when the iTunes Music Store was brand new, you can still apply the cost of that track towards the purchase of the full Frampton Comes Alive! album.  

Since it came online, the iTunes Music Store has sold about 2.5 billion songs, and about 45 percent were purchased as full albums.  

Read more at Business Week.