Adsense

AdSense is an advertisement application run by Google. Website owners can enroll in this program to enable text, image, and more recently, video advertisements on their websites. These advertisements are administered by Google and 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).
http://en.wikipedia.org/wiki/AdSense

If you interesting with Adsense, u must have a website or blog to publish the sponsor.
just follow this link www.google.com/adsense