Google adsense is a program run by google inc. That allows
publishers in the google network of content sites to serve automatic text,
image, video, and rich media adverts that are targeted to site content and
audience. These adverts 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$2.43 billion ($9.71 billion annualized), or 28% of total revenue,
through google adsense.
