It will surprise no one that Google accounts for a lion's share of the ad server market. However, it may come as a shock that Microsoft holds only the equivalent of a lion's paw.
Attributor, a content-tracking company, analyzed ad server calls across 75 million domains in October. According to the data Attributor released this week, Google--through DoubleClick and AdSense--accounts for 56.5 percent market share.
Meanwhile, Microsoft's equivalent figure hovers at 3.8 percent. Yahoo came in behind Google with 9.7 percent. If Microsoft and Yahoo ever end up combining forces, they still wouldn't touch Google.
A server call, by the way, is the "moment when a Web site requests an ad to serve up to a user. The study examined whose ad code was on that page," according to AdAge.com.
DoubleClick and AdSense are definitely playing to different markets, according to Attributor's figures. DoubleClick dominated with larger sites, while AdSense did so for smaller sites.
It's not all good news for Google, though. Back in Janary, when Attributor last took a look at ad server calls, Google's AdSense and DoubleClick accounted for 69.7 percent share. That's a drop of more than 13 points.
Google didn't lose out to Microsoft or Yahoo, though. They also lost share. Instead, Google lost little bits to a lot of other players, including AOL and Revenue Science. The latter shot into the top five with 6.7 percent market share in October.