As a publisher you want to make the most money for your inventory. A publisher is someone who has advertising inventory in the form of text ads on a site, banners, video ads, audio ads or any type of advertising. Banners and text advertising have been around since the 90s and multiple advertising networks have provided inventory fulfilling technologies.
Systems have been developed by third party companies to optimize the fulfilling of inventory for the best return for advertisers as well as publishers. In the past you would manually swap out code on your site to deliver ads from those paying you the most for that inventory. Now it can be done for you with ad optimizing technologies.
Thirteen predictions from CEO’s of these top publisher technologies can be found here from the AdExchanger site. Learn the predictions for 2011 at their site, I will not steal their thunder here.
You will notice many reference RTB which stands for real-time bidding. The basic idea is to help both advertisers find the best audience at any time as well as obtain the highest eCPM for publishers. The eCPM is an estimated cost per thousand as not all payouts are based on fixed prices, therefore when a CPC (cost per click) is utilized the CPM must be estimated over time. To learn even more about Real Time Bidding see the white paper found here at the PubMatic site.