Affiliate marketing is a marketing channel where online publishers (or affiliates) drive traffic to your site. Rather than paying for the traffic, you pay when, and only when, that traffic converts and becomes a sale. Or a signup. Or registration. Or whatever it is you want people to do.

Online publishers include voucher and cashback sites, price comparison, shopping sites. They include technology partners that recapture un-converted traffic, email marketers, paid search partners, call tracking services and more.

These days it’s often called performance marketing. Because you pay for performance.