1) Affiliate marketing involves businesses rewarding affiliates for marketing efforts that bring visitors or customers. It is a revenue sharing model between a website owner and online merchant. 2) There are three main ways affiliates can earn money: pay per click, pay per lead, or pay per sale programs. 3) Affiliates include coupon/discount websites, shopping directories, search affiliates, personal blogs, and niche product sites. Setting up an affiliate program has low startup costs and various monetization options for new entrepreneurs.