What's a suspicous credit card transaction look like? Here are a few warning signs:

1) Ordering multiple copies of an electronic product (yes, some people do order multiple copies, but very few)

2) Multiple failed transactions with different names/credit cards leading up to a successful transaction

3) An email bounce from the buyer. Sometimes these are just typos. But other times they can mean fraud.

4) All of the above happening in a single affiliate account.

If you spot a fishy transaction, and can not reach the buyer, simply void it. This will protect your merchant account from a chargeback. And always remember to void the appropriate affiliate commission.

If you notice a pattern of suspicious transactions originating from a particular affiliate, fire the affiliate! In many affiliate programs, this can be as simple as changing their commission level to zero percent.