1. A method for maximizing page yield in the display of advertisements to searching Web users, the method comprising: tracking click activity associated with a plurality of advertisements displayed to a plurality of users through a hierarchal set of search results pages associated with a keyword; tracking bidding activity by a plurality of advertisers related to the keyword and corresponding advertisements of the plurality of advertisements; applying at least one component model to the click or bidding activity as correlated with a particular search results page of the hierarchal set of search results pages via which the advertisements receiving the click activity are displayed, wherein the at least one component model generates a set of output values representative of the tracked click activity; and providing the output values to the at least one component model to iteratively optimize a number of advertisements displayed on the particular search results page via which at least some of the advertisements are displayed in response to a query for the keyword.