A Commercial Advertising Revolution: From Yellow Pages to Search Engines

Over the last three decades, the search process for commercial information has changed fundamentally. The move from yellow pages to search engines has been accompanied by fundamental changes in the advertising model. These changes are argued to arise from three main differences between media technologies: content “depth,” display space, and cost structure. The printed yellow pages are unconstrained in paper space, as new pages are easily added, so pricing was based on the size of the ad. Sea