The affiliate program is a program that allows someone to promote your service. When an affiliate sends traffic to Legiit through their affiliate link it cookies the buyer to them for 15 days. The percent paid for someone else promoting your service is 15%.
You can tell if a sale has been referred by and affiliate by going to Sales > Orders and looking at the affiliate column.
An example of a payment structure would be:
Order Total = $100
Affiliate Commission = 15%
Legiit Commission = 10%
$100 (total order) - $15 (Affiliate) - $10 (Legit) = $75 paid to seller