Mobile ad network Millennial Media has released its monthly report into the performance of each OS, device and manufacturer, breaking out the impression share of each platform. In August Android was on top with a 54% share, followed by iOS with 28% and RIM with 13%.

Android impressions grew 48% month-on-month globally, while iOS remained relatively flat. However, Apple has continued to be the leading device manufacturer in the network in August, with 13% of the Top 20 Mobile Phones impression share; all Android phones put together accounted for 32%. Overall, smartphones grew 6% month-over-month, taking 72% of the impressions in August. Connected Devices and Feature Phones were tied with 14% of the impression share.