Yes, Yahoo! may have the largest percentage display ads overall at the moment, but there is David arriving in this David & Goliath story. Perhaps I should refer to David in the plural and they are just starting to hit the radar on your comScore chart.

David(s) comes in the form of vertical ad networks. No, not the remnant horizontal ad networks that serve up the junk-food inventory. It’s the vertical ad networks exclusively representing the long-tail of the sites within the content vertical.

For example, companies like Glam Media, JumpStart Automotive media (AUTO) , Netshelter (TECH) and Travel Ad Network (TRAVEL) are are becoming the #1 display audiences in their respective categories and garnering Goliath-like ad revenues.

With portals becoming irrelevant, and search engines not capable of servicing display advertising adequately, will the Goliaths become prey to David’s well-aimed slingshot?