According to the results of a recent comScore study of vertical ad networks, targeting ads to specific audiences online according to demographic or category content, the collective reach of vertical ad networks tracked has increased substantially in the past year, from 21.5% of the total U.S. Internet audience in March 2008 to 57.1% in March 2009. Vertical ad networks tracked include entities such as Adify Media, Federated Media, Glam Media and Travel Ad Network, among numerous others. Growth in Vertical Ad Network Reach (Total U.S., Home/Work/University Locations) CategoryMar-08Mar-09Percent Change (2009) Total U.S. Internet Audience 188,010 192,173 2% Vertical Ad Networks, Unique Visitors (000) 40,343 109,757 172% Vertical Ad Networks, Reach (%) 21.5% 57.1% 166% Source: comScore, April 2009 Lesle Litton, VP, Media at comScore, concludes that "... as more vertical ad networks prove their ability to effectively reach specific target audiences by aggregating... publisher sites... the industry will likely give greater consideration to these emerging ad delivery channels." The study shows that vertical ad networks are effective in reaching people with significantly higher than average engagement in their respective content categories. Of the five segments studied, people reached by vertical ad networks spent at least 60% more time in those site categories than the average category visitor. People reached in the Gaming segment spent 423 minutes per visitor on sites in that category, 123% higher than the average visitor. Engagement of People Reached via Vertical Ad Networks (March 2009 Total U.S. - Home/Work/University Locations) Site CategoryAverage Minutes per Visitor?People Reached by Vertical Ad NetworkAverage Category VisitorIndex* Gaming 422.9 190.0 223 Entertainment 417.8 191.4 218 Community 136.2 82.1 166 News/Information 123.8 77.3 160 Health 54.2 31.7 171? Source: comScore, April 2009 (*Index = Time Spent by Vertical Ad Network visitors / Time Spent by Category Visitors x 100; Index of 100 indicates average representation) For more information from comScore, please visit here.