You’ve probably heard about people who use e-commerce websites and large online stores or affiliate marketing networks as their affiliate partners. Usually, these people get a very small cut of the profits and have to compete with all of the other thousands of people out there, who are also trying to see bicycles and computers using websites like Amazon.
For CPA-based programs, you need to understand their payment structure and the restrictions in the promotion. CPA is an excellent opportunity to make real money by promoting the right products. Choose this type of program if you’re keen to get a variety in the commission range. Tip: Without a $1+ commission, you shouldn’t select a CPA program.

People are very used to “referral links” where someone recommends a product or service they use via a link inside their account. In return for the referral you may get a free month or other benefit from the referral. It’s a common way apps grow their user base.
Essentially, affiliate marketing is a form of profit-sharing between sellers and advertisers. The commission earned comes out of the product price, so it doesn't create an additional cost to the customer.