Apple CEO Steve Jobs revealed this week that the iTunes Store is now the fifth-largest seller of music in the U.S. During his presentation at Apple’s “Showtime” event on Tuesday, Jobs cited data from NPD that showed Apple has moved into the No. 5 spot among music resellers, behind Wal-Mart, Best Buy, Target, and Amazon. Jobs said it was a milestone because iTunes is the first digital music store to make it into the top five, which is dominated by store’s that only sell physical CDs. What’s more, Jobs said the iTunes Store is on target to pass Amazon to become No. 4 in the first half of next year.