This is an interesting story about how Google’s AdSense program was perverted by folks who understood the nature of arbitrage.

http://www.financialpost.com/magazine/story.html?id=324817

The real gem of the story is the following:

In 2003, Google made another huge leap forward on the advertising side, with the launch of its AdSense program. Essentially, this application allowed people to put keyword-targeted ad links, served by Google, on their own websites, with them and Google splitting revenue tied to the volume of user click-throughs. As its popularity grew, a cottage industry began to develop called “search arbitrage.” Essentially, search arbitrage involves an individual or company buying Internet traffic through the acquisition of keywords from Google, then sending viewers who click on the ad links to a site (“landing page” in Google terminology) that appears to have content, but is actually just full of online advertising linked to the original search term. Anyone clicking an ad link there makes money for the keyword holder. For example, a company might bid for the Google rights to the phrase “small town car sales” and send traffic to a website it controls, filled with more car advertisements, called “Alltheautomotive.com.” The keyword cost only 20¢, while a click on the advertising on the website might yield $1.50 return. According to Niki Scevak, an analyst at Jupiter Research in New York, the majority of those initially involved in search arbitrage were small players. “These were guys running search arbitrage out of their basements, making maybe $20,000 a month,” he says.

Essentially you buy “cheap” words, and populate the web page with expensive words and make a killing on the difference!

And this is legal…