Pay per click (PPC) is an Internet advertising model used on search engines, advertising networks, and content websites, such as blogs, where advertisers only pay when a user actually clicks on an advertisement to visit the advertisers' website. Pay-per-click advertising (PPC) allows your business to advertise on the pages served by search engines when a user searches for a specific keyword - placing your business in front of people actively searching for your products or services.

The use of PPC advertising has grown substantially over the past few years and now represents the one sector of advertising - both online and offline - with the highest increases in annual spend. PPC is also the part of the search engine business that has provided the exceptional financial growth for the likes of Google and Yahoo!, as many companies have started to use this form of targeted advertising and therefore the average cost for buying position within the sponsored listings has also increased.

With search engines, advertisers typically bid on keyword phrases relevant to their target market. When a user types a keyword query matching an advertiser's keyword list, or views a webpage with relevant content, the advertisements may be displayed. Such advertisements are called sponsored links or sponsored ads, and appear adjacent to or above the "natural" or organic results on search engine results pages.