Adsense History

   Google launched its AdSense program, originally named content targeting advertising in March 2003. The AdSense name was originally used by Applied Semantics, a competitive offering to AdSense and then adopted by Google after Google acquired Applied Semantics in April 2003. Applied Semantics was started in 1998 by Gilad Elbaz and Adam Weissman. Some advertisers complained that AdSense yielded worse results than AdWords, since it served ads that related contextually to the content on a web page and that content was less likely to be related to a user's commercial desires than search results. For example, someone browsing a blog dedicated to flowers was less likely to be interested in ordering flowers than someone searching for terms related to flowers. As a result, in 2004 Google allowed its advertisers to opt out of the AdSense network.

    Paul Buchheit, the founder of Gmail, had the idea to run ads within Google's e-mail service. But he and others say it wasSusan Wojcicki, with the backing of Sergey Brin, who organized the team that adapted that idea into an enormously successful product. By early 2005 AdSense accounted for an estimated 15 percent of Google's total revenues.

   In 2009, Google AdSense announced that it would now be offering new features, including the ability to "enable multiple networks to display ads".

   In February 2010, Google AdSense started using search history in contextual matching to offer more relevant ads.

   On January 21, 2014, Google AdSense launched Direct Campaigns, a tool where publishers may directly sell ads.
   Google AdSense is probably the most popular advertisement service on the web. By including a specific javascript code in your web site, it allows you to generate revenue though different advertisements related to your web site content. The amount of generated income is based on the type of advertisements and the number of clicks on them.

Your income is generated both from clicks on ads and from impressions (number of times the advertisement is shown on your web site).

   Besides the clicks and the impressions, you can earn money by including a Google search box in your web site code. If your web site visitors use it you will get a percent of the profit relevant to their search terms. AdSense for Feeds and AdSense for Domains are also available . The first one places ads in the feeds managed by Google for your web site. The second one allows advertisements to be included for domains that do not  open a web site with content.