Mobile advertising firm Millennial Media today announced the release of its "Mobile Mix" report covering device, operating system, and revenue share for the month of April. After receiving a bit of a boost in March, Apple's iOS platform has dropped back from 31% of the total ad impressions seen on the network to 28%. Conversely, Android has bumped back over the 50% mark to grab 53% of impressions.
But despite Android's growth on the ad impression side, iOS continue to hold its own on the revenue side, as both iOS and Android gained three percentage points at the expense of other players, with iOS improving to a 50% share of mobile revenue. Android stands in second place at 39%, while Research in Motion improved by two percentage points to 9%. Those gains came against a huge drop in revenue for "other" platforms, which include Microsoft's Windows Phone 7, Nokia's Symbian, and Palm's webOS.