So says this NYT story: Micropayment service providers may have gone bust in the last couple of years, with companies like Yaga, Bitpass, Peppercoin and others closing, but 99 cents for a song on iTunes and other places is a micropayment. So are the tiny amounts CPC ads, as well as stock-photography companies pics on the lower end. “Closed loop” systems like iTunes are the most successful in getting piecemeal payments from users, the story says.

The usual litany of problems for other systems: credit card charges for such a small payment is too high for vendors, user-resistance to small payments, etc.