title: Need to understand how programming is done for cashback kind of websites
body: <p>I have to develop a website which should give user some cashback based on his purchase on some referred website. For example, my site is cashbacktest.com and it will give users cash back coupon options for other websites say wallmart.com.</p>
  
  <p>Now I do not understand how to code for this. I am using ASP.NET and have the following queries:
  1. How will I get to know whether the user has actually made a purchase on the referred website.
  2. As there could be many sites where I will refer from my cashbacktest.com, how will I code/progam to get a response  for purchase from the referred website.
  3. Don't know if I have to work with each referred website to ask them to send me back some response code after successful purchase.</p>
  
  <p>Some of the examples of referral or cashback based websites are ebates.com, deals2buy.com and many more.</p>
  
  <p>Any advise on how to proceed would be appreciated.</p>