Affiliate Marketing is a scheme where brands enlist other websites to display their banner ads (or other types of ads) in return for a a percentage of the traffic or revenue that results from those ads.
The most common affiliate marketing programs are based on pay-per-click, pay-per-sale or pay-per-lead.
Affiliate marketing is a risky proposition and most digital marketers do not find it effective. Why? Because the commission or fee paid to the websites displaying the ads often is not worth the impact on the brand itself. With affiliate marketing, a brand often loses control of their messaging context (what type of content is on the page or website where they appear) and they may also surrender customer experience and customer service.