Earn Money from Google.

Google AdSense is a program run by Google Inc. which enables publishers in the Google Network of content sites to automatically serve text, image, video, and rich media ads that are targeted to site content and audience. These advertisements are administered, sorted, and maintained by Google, and they can generate revenue on either a per-click or per-impression basis. Google beta tested a cost-per-action service, but discontinued it in October 2008 in favor of a DoubleClick offering (also owned by Google).In Q1 2011, Google earned US$2.34 billion ($9.36 billion annualized), or 28% of total revenue,

How AdSense works

• The webmaster inserts the AdSense JavaScript code into a webpage.
• Each time this page is visited, the JavaScript code uses inlined JSON to display content fetched from Google's servers. 
• For contextual advertisements, Google's servers use a cache of the page to determine a set of high-value keywords. If keywords have been cached already, advertisements are served for those keywords based on the AdWords bidding system. (More details are described in the AdSense patent.)

For referrals, Google adds money to the advertiser's account when visitors either download the referred software or subscribe to the referred service.The referral program was retired in August 2008.

Search advertisements are added to the list of results after the visitor performs a search.