An interesting article from AdBumb.com posits that banner advertising networks are selling their inventory using the CPA model — unknown to the publishers as well as investors. Said to be a hush-hush but common industry practice, banner ad networks resort to negotiating CPA deals with advertisers in order to sell their low-quality inventory. Afterall, it looks better to the shareholders that all inventory was sold out, never mind if the publishers were tricked to believe that they showed CPM banners only:
Talk to anyone who knows much about online advertising and you’ll hear quickly that some of the bigger networks like Fastclick, Casale Media and RightMedia are running CPA offers without actually advertising the service. Dig around a little more and you’ll find that this is true across the board on many networks. But try to get these networks to admit they’re doing it and you often run into a brick wall
