Hi --

Hypothetically speaking, how could I accomplish this task:

Suppose I have 2 affiliate programs set up on my site; Amazon.com and Pets.com. And let's say I want to give my visitors who shop at these stores through my links a 10% cashback bonus on their purchases.

How can I track their purchases back to them? I know I can verify all purchases made through my Amazon or Pets account reports, but how can I determine which visitors made what purchases and for how much?! Do I need to use cookies somehow? Do they need to "Login" somewhere first before shopping?

Any help or ideas how this can be accomplished would be greatly appreciated.

Thanks,
Joshua