BBC NEWS | Business | Lessons from Silicon Valley

"But Excite took the conventional view that the ads would come from the top 100 companies in the USA, the people who buy huge amount of TV time and blanket the newspapers and the magazines.

Google did not go for the big spenders. Google's squads of PhDs wrote algorithms that would make it viable for the company to take hundreds of thousands of ads from hundreds of thousands of small (or big) companies, and pop the ads up in highly relevant spaces close to the search lists."