Apple has long reigned as the top device maker based on traffic to Millennial Media's mobile network. But its reign could be challenged by its archrival.
Apple scooped up 31 percent of all ad impressions during the third quarter, according to the ad network's latest Mobile Mix report. That level was virtually unchanged from the second quarter.
In comparison, Samsung captured almost 25 percent of all impressions for the third quarter. That number was up from just under 22 pecent the previous quarter.
Among the top 20 mobile phones, the iPhone was the leader with 16 percent of all ad impressions. But eight Samsung phones scored a spot on the list, more than any other manufacturer. Collectively, those eight phones grabbed more than 13 percent of all impressions.
Among other device makers, HTC took third place with a share of 7.96 percent, followed closely by Research-in-Motion with 7.9 percent.
Looking at mobile operating systems, Android made up 52 percent of all impressions on the ad network last quarter, up from 46 percent in the second quarter.
Apple's iOS took in 34 percent, unchanged from the prior quarter. However, iOS 6 gave Apple a shot in the arm.
Following the debut of iOS 6, the volume of impressions found by Millennial Media were 1,200 percent higher than those seen last year after the release of iOS 5. For this stat, the impression numbers cover all iOS devices, including the iPad and iPod Touch, not just the iPhone.
Android and iOS virtually own the moble marketplace, leaving other operating systems with tiny pieces of the pie.
For the third quarter, RIM's BlackBerry OS snared 8 percent of all ad impressions, down from 15 percent the prior quarter. Microsoft's Windows Phone eked out 5 percent, a small gain from 4 percent in the second quarter. And Nokia's Symbian stayed flat with a 1 percent share.
Millennial Media captures and compiles data from its mobile ad network, recording tens of billions of ad requests each month, according to the company.