AdSense

Google AdSense, commonly just AdSense, is an ad serving program run by Google. Website owners can enroll in this program to enable text, image and, more recently, video advertisements on their sites. These ads are administered by Google and generate revenue on either a per-click or per-thousand-impressions basis. Google is also currently beta-testing a cost-per-action based service. Google AdSense is a free and easy way for website publishers of all sizes to display relevant Google ads on their website's content pages and earn money. The ads are related to what your visitors are looking for on your site — or matched to the characteristics and interests of the visitors your content attracts. AdSense for content automatically crawls the content of your pages and delivers ads (you can choose both text or image ads) that are relevant to your audience and your site content—ads so well-matched, in fact, that your readers will actually find them useful. AdSense for search allows website publishers to provide Google web and site search to their visitors, and to earn money by displaying Google ads on the search results pages