http://www.google.com/ads/georgewashington.html

The George Washington University Medical Faculty Associates is a health care practice in Washington D.C. One of the more popular services is their fertility care.  The media and marketing manager, David Garofalo, had previously used print and radio advertising to get perspective clients. Specifically he searches for potential egg donors. With print and radio advertising he got about two or three inquiries per month.  Garofalo then decided to use Google AdWords as his main outlet and began to get three or four inquiries per day. This 2000% increase helps the clinic because it gives a deeper pool of egg donors to choose from making it easier and faster to pick a donor. Garofalo believes that AdWords gives him more control over his advertising budget because he can see which keywords are generating the most hits and which ones aren’t. He is able to change his ads at any time unlike print ads which run for a set period of time. 

This article describes an instance of using keyword based advertising. Google AdWords prides itself on being a cost-effective way to advertise. This is because it uses the “cost-per-click” method, giving advertisers broad options of keywords and then being able to pick the most popular ones. Using a form of Overture’s method (the “kind of” second price auction), Google AdWords sells keywords, charges by number of clicks and sells multiple slots.