After arguing for years that the success of its iTunes Store rests on low, standardized pricing, Apple on Wednesday unveiled a new feature of the online service, called Complete My Album, that was directly requested by the music industry. Users who purchase individual songs on iTunes can now buy the rest of the album via the service for a discounted price.

"Music fans can now round out their music collections by upgrading their singles into complete albums with just one click, and get full credit for those songs they have previously purchased from iTunes," says Apple vice president of iTunes Eddy Cue. "Complete My Album is a wonderful new way that iTunes helps customers grow and enjoy their music collections."

Previously, iTunes customers who purchased individual tracks from an album were not credited for those purchases if they later went back and purchased the entire album, meaning they were effectively charged for certain songs twice. Now, customers will receive a 99 cent credit for each song they purchased from an album when they later go back and purchase the full album.

As you might expect, there are restrictions. Customers have 180 days after purchasing any individual track in which to purchase the full album in order to qualify for the discount. And track purchases made before the Complete My Album system went online do not qualify for the discount.