pre-paid

'Micro payments' seem to be a good alternative to generating revenue for various types of sites. For example, a gaming company charges pennies for their users to buy clothing items to decorate their virtual creatures. They have their users pre-pay for these purchases in advance (a $25 pre-payment). Then when a user wants to buy a hat for their character, their account can be debited that amount (maybe $.10). This reduces the costs of processing the micro payments and opens up many new possibilities for revenue generation.