a pricing model based on delivering sales or something else that can be directly attributed to the bottom line. Contrast this with traditional banner advertising which is based on impressions, a chunk of which come from people you have no desire or ability to do business with. [ edit
A system nearly identical to Pay-Per-Click, and can be synonymous.
Term popularized by some search engines as a synonym for pay-per-click, stressing to advertisers that they are only paying for ads that "perform" in terms of delivering traffic, as opposed to CPM-based ads, where fees are based on impressions or views instead of clicks.