nBill

Post Affiliate Pro (PAP4) can be integrated with nBill by installing extension that can be downloaded here. All you have to do is install the extension, and enter the path where you installed PAP4 (by going to Extensions->PAP4 on the nBill menu after installation). Every payment you receive through an nBill payment gateway will then be registered through Post Affiliate Pro, and if the payment was initiated by a computer with a PAP4 cookie, the commission will be awarded to the referring affiliate