PPC stands for Pay-Per-Click, and it is the placement of an advertisement on the search engine result pages (SERPs) for a specific keyword phrase in return for specified payment when a visitor clicks on the link. The PPC link is also known as Sponsored Link, and the advertiser pays an agreed (or bid) amount each time a visitor clicks on the link.

The advertiser generally places PPC advertisements on the search engines in the hope of selling products or services on their website. The job of a PPC link is to send targetted traffic to the website (landing page). Regardless of the visitors spending money on your website, you're obligated to pay the agreed sum to the search engine company. One more thing to note is that the advertiser pays nothing to make a sponsored link appear on the SERPs, but pays the fee only when someone clicks on it.

The biggest two PPC providers are Yahoo! Search Marketing, formally known as Overture, and Google Adwords. The MSN AdCenter is another PPC gaining popularity.