That Android factoid is among the latest examples of the inroads the Google mobile platform has made against the iPhone and Apple's iOS operating system. Android remains the second-largest smartphone OS on Millennial's network, generating 29% of impressions -- up from 26% in August, compared to 46% for iOS. Android ad requests were up 26% in September, and have grown 1,283% since January.
Among individual handsets, the Android-based Droid X has surged ahead of the BlackBerry Curve into second place behind the iPhone, accounting for nearly 10% of impressions on Millennial's network. The Droid's rise has come at the expense of the iPhone, whose share has fallen off steeply from about 24% in July to 19%. Looking at all manufacturer devices -- including the iPod and iPad -- Apple is tops with a 30% share of impressions, down from 35% in July.
Android's ad gains reflect its underlying growth as a platform -- becoming the top-selling smartphone OS in the last six months, according to a recent Nielsen report. In its third-quarter earnings call last week, Google for the first time disclosed mobile ad revenue, estimating sales at $1 billion on an annualized basis. The vast majority of that amount is from mobile search, but Google CEO Eric Schmidt reiterated the company's commitment to expanding in mobile broadly.
While Google aims to challenge Apple in the tablet market as well with the Android-powered Galaxy Tab, the iPad has an early advantage. Revenue generated by the Apple device in the third quarter increased 316%, while impressions tripled.
The number of advertisers grew 94%, according to Millennial. Overall, however, the proportion of connected devices on the ad network dropped to 13% from 19% two months ago. The share of impressions driven by smartphones increased 7% in September to 58%, while feature phones rounded out the device landscape with a 29% share.