One guy had 4 sales. Two were chargebacks. I refunded the other two of his after the chargebacks to prevent any more chargebacks. These sales had fake email addresses for the buyers ... email addresses that bounced when I emailed them. The commissions were not returned to me at all, even though they were processed through the platform as requested, so this guy got to keep the nearly $200 in commissions he made. Same with the other one, a girls' name who made one fraudulent sale resulting in an unauthorized transaction chargeback to my Paypal account.
That's nearly 1/3 of the sales from these affiliates that were fraudulent sales.
Lessons are often learned after the fact, but here's one for you.
Do not do "instant payments" to affiliates, unless you know them. Of course the site in question warns that, but the instant commissions are a nice benefit for affiliates ... if you could trust them. And of course, you probably don't know very many of the affiliates who apply. I denied approval to quite a few based on things like location and the fact that they didn't respond to my email that I sent them questioning them how they planned on promoting my offer, so I thought I was being careful by contacting them first before approving them. It wasn't enough, apparently.
I still have no idea what those two affiliates did to get sales that resulted in unauthorized transactions. As I said, I'm new to allowing affiliates to promote my products. If anyone knows what these scammer affiliates do, let me in on it.