Does anyone know of a good billing script that uses a CREDITS system. That is to say that customers buy credits for certain things and can then use these credits to buy goods or services. I.e. they may buy 20 domain name credits for example and then could register 20 domains as and when they want. I've seen these systems implemented before and think that they work very well, especially if you do not want to offer real-time card processing for goods and services.

Thanks.

H-Sphere *might* do this... (psoft.net)

Neofree