Pay-Per-Click (PPC) advertising is a model in which an advertiser is charged a specific fee each time a user clicks their ad and is transferred to another Website. This is different from the impression-based, or CPM model (cost per 1,000 impressions), which is standard in traditional media and graphical interactive advertising. With Search Engine Marketing, the price per click is often determined by a free-market auction. The higher the bid, the higher the advertiser’s message will appear on the search engine results pages. Some examples of well known Pay-Per-Click advertising networks are Google’s AdWords network and Yahoo!’s Overture network. Also known as: Pay For Placement (PFP, P4P) and Paid Placement.