Millennial Media is out with its July Mobile Mix report (highlights after the jump). The mobile ad network releases the report monthly, covering activity on its network. This most notably includes the mobile devices, operating systems and apps where it’s seeing the most ad requests and impressions.
Though this isn’t directly representative of the entire market — including only activity on its network — it’s directionally relevant to see how mobile advertising activity is shifting over time. It’s also a fairly large sample if you consider that Millennial reaches 63 million of the 77 million U.S. mobile Web users (Nielsen).