I am designing a web app, which needs a payment model. I am looking for a module similar to the one on skype (which is prepaid). As in you can transfer some credit to your account and that amount will be pre-paid. After that you can use that amount for various stuff on the website.
Firstly, i would like to know if there are reusable or open source modules which can be used for this type of payment model.
Secondly, I would like to know if there are any issues of this model. Are there any extra things that you have to be sure of if you are doing with this type of payment model.
-AJ