Analysis of the mobile Web browsing habits of over three million people has revealed previously unseen patterns in how the major advertising companies carve up the Internet. Among the findings of a new study is that Google’s advertising tentacles extend to at least 80 percent of online publishers. It also found that if only a small fraction of Web surfers opted out of being shown shown ads based their previous online behavior, it would significantly decrease the industry’s profits.
The new study was carried out by academics at Stony Brook and Columbia universities, with researchers from two major telcos: AT&T in the U.S. and Telefonica in Spain. They used records of 1.5 billion mobile Web surfing sessions from 2011, supplied by an unidentified mobile network operator, to see which sites people visited and which online ad companies provided ads on those pages.