Mobile ad network Millennial Media ( has released its quarterly report that shows how each operating system, device and manufacturer is performing on one of the largest remaining independent ad networks in the world.

The report notes that the iPhone and iPad ranked first in various mobile advertising statistics for the third quarter of 2011, though Apple’s iOS had a 28% share of mobile ad impressions — or half of the 56% seen by Android devices. In the third quarter, Android led the Connected Device and Smartphone OS Mix on Millennial with 56% of the impressions. iOS was the second largest Connected Device and Smartphone OS in Q3 with 23% of impressions.

iOS remained the leader as the top Connected Device OS. iOS impressions grew 60% year-over-year in the third quarter. What’s more, iPad impressions grew 456%, and iPod touch impressions grew 30% year-over-year. The iPhone accounted for 54% of the iOS impressions Millennial’s platform, while the iPod touch and iPad combined to make up the other 46%.

Apple was the top device manufacturer on Millennial Media’s platform in the third quarter, representing 23% of the top 15 manufacturers impression share with 12% of the impression share on the top 20 mobile phones ranking.