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 they get a % of the sale as commission. 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 = 15%
$100 (total order) - $15 (Affiliate) - $15 (Legit) = $70 paid to seller