Pay Per Click. A targeted online advertising method where an advertiser is charged only when an ad is actually clicked. PPC campaigns can be either flat-rate or bid-based where advertisers can more highly target campaigns based on various parameters including keywords or URLs similar to Cost Per View advertising.
Example: You bid $1.00 for the keyword “making money online.” Then, when a potential buyer is viewing something related to making money online, and If no other bid exceeds yours, your ad is displayed and (only) if they click on your ad, you are charged $1.00 for the click.