News that ESPN.com plans to start selling directly to its advertisers adds fuel to the debate over the merits of online ad networks and what kind of sites can most benefit from them.The huge sports site is among a growing list of big online publishers who are opting to either go it alone, or at the very least keep control over most of their ad inventory -- especially the chunk targeted at brand advertisers based on data about the Web site's own users. At the same time, big online media companies like AOL have been buying ad networks to get control of relationships with those same brand advertisers. So where do ad networks and ad technology platforms like Adify fit ... [ Read more ]