I was thinking about the same situation.
Trying to adapt Drupal's Affiliate module for E-commerce seems very complicated.
I thought of creating a role for affiliates, so that they could login and enter the orders manually (from the customers they get). However, as I mentioned on other thread, when an affiliate was granted this role, they could also modify the orders created through our own site. Ryan said that once an order is created, it goes into edit mode. So I don't think of handling affiliates through roles.

I would really like to see if someone comes up with any other idea.