What Pay-Per-Click (PPC) is: online advertising wherein the advertiser pays for the ad when it is clicked. Click price can either be a flat rate or determined based on a bidding system.
What Pay-Per-Click (PPC) is not: Pay-Per-Impression. In a Pay-Per-Impression system you pay for each (you guessed it) impression of the ad, rather than for each click on the ad.
Why we care about Pay-Per-Click (PPC): Pay-Per-Click advertising is the system The Big Guys (Google, Yahoo, Microsoft) provide for your to advertise on their networks. You need to know how it works in order to reach the largest audience.
This post is part of an ongoing Clickipedia series, defining all the terms you need to know for conversion rate optimization. Keep checking back each week to learn more, and don’t forget to check out the whole series.