Yahoo! also uses advertisement system based on the content of a page.
Yahoo! has launched its advertisement system in February 2007.
“ Advertisers will simply enter the keywords they want their ad to appear next to and the maximum price they are willing to pay for a click. The most significant option will be to specify a certain geographic region in which the ads will be shown, a feature Google also offers. “ ¹
“ as advertisers enter each bid, they will see an estimate of how many clicks they will receive each day. More important, a graph will show how many more clicks they can expect for each increased bid.” ²