An advertising network to watch

I just heard news of Proximic which has reportedly signed deals for ad inventory with both eBay’s shopping.com and Yahoo’s Shopping Network.
This is the first time that these two companies have licensed their inventory, and it gives Proximic an inventory of over 50million unique ads (compared with Googles 1million) - 20m from each of those mentioned above and 10m from another un-named source.
Proximic is said to deliver context sensitive ads in a novel mathematical way that is more effcicient and faster than Google’s current methods.