On the face of it, it’s reasonable to assume that Yahoo’s decision to shutter its Publisher Network two months ago has likely caused a significant drop in the company’s share of the ad serving market. But the YPN was too small to really count. Instead, the decline in share likely has to do with two other changes at Yahoo.

SEE ALSO: Yahoo Gives Up On AdSense Clone; Publisher Network Handed Off To Chitika

First, Yahoo is putting more resources in its direct display sales, something that has paid off as those revenues rose 20 percent in Q1. So Yahoo’s volume has likely declined as a result. Secondly, reason for the change cited by Attributor is that that the figures are based on Compete’s traffic stats, which doesn’t go as deeply as comScore’s, and tends to overlook the volume from Yahoo ad exchange Right Media’s YieldManager ad server name. The number also might not include Yahoo’s Blue Lithium ad network.

In any case, given Google’s dominance—alone its AdSense system has 36.59 percent of the market, up from 25.8 percent in ‘08—it makes sense that Yahoo has largely given up on mounting a serious challenge in ad server realm. And at this point, Yahoo’s interest in growing its online ad server calls is probably an even lower priority than its desire to drive higher search share.