Mpayy brings up an interesting point about eCommerce:

High cost payments – credit cards & bill-to-carrier models – won’t meet the needs of micorpayments beyond digital sushi. http://mpayy.me/7W

As the eCommerce article reports, virtual goods are one of the top new trends in internet marketing. Virtual goods are small, digital items that users can purchase for a low price. They are usually coupled with micropayments- very small payments for a good or service. You can find examples of both on popular social networking sites, at music stores, and other places on the web.

Unfortunately, the micropayment business model makes it tricky to use a credit card for each individual payment. Since each payment is so small, it can be difficult for merchants to overcome the fees associated with a transaction. For that reason, many merchants develop alternative payment systems. If you ever see a request to purchase a minimum number of credits, you’ll know the reason why: a merchant wants to make transaction fees worthwhile. Even in the world of micropayments and virtual gifts, costs are still a very real thing.