There are two main types of affiliate selling. The first is if you become an affiliate for somebody else. You promote the product or service or refer it to others, and if one of the people you refer it to buys the product because of your referral, the product owner gives you a commission. The other is where you have a product and someone else becomes your affiliate. They promote your product, and if someone buys your product because of their referral, you pay them a commission.