This was Ahmad's Question ;-

Subject: Ecommerce Subscription Systems database
Question: hello all how are you
i want to build a database for Subscription System that i can give a different ways for the customer to pay for my service
that i want to supply in my application like:
Pay per click (PPC or CPC)
Cost Per Action (CPA or PPA)
Cost per impression (CPI or CPM)
and the other ways of payment and so any body can help me
if there are any applications or open source or references for this problem
thanks............