The series is essentially trying to make the case for self service advertising.<p>It makes sense. GAM and OpenX are good systems that will both work well for people that rely (or want to rely) mostly on ad networks and occasionally get a few direct sales enquiries.<p>However once you move into the realm where lots of advertisers are contacting you directly, it is much much better to have an self-service ad management system.<p>Think of Facebook, it makes a large majority of its revenue from self-service advertisers. Not GAM, not OpenX but Facebook Ads. 
<a href="http://digital.venturebeat.com/2009/09/18/facebooks-self-serve-ads-crushing-it-lead-to-profitability/" rel="nofollow">http://digital.venturebeat.com/2009/09/18/facebooks-self-ser...</a>