AdMob's latest mobile metrics report (which tracks ad clicks/requests by phone, OS, and geographic location) looks not only at the iPhone vs. Android-phone battle, but the battle between various Android phones themselves.
F'rinstance: last fall, two phones from HTC (the Dream and Magic models) dominated the Android handset field. Today, the Moto Droid and HTC Hero are the "alpha robots" (32% and 19% ad request share, respectively). with everything else duking it out in the lower ten percentile. (Oh, the Nexus One? Barely a blip on the radar with 2% share…)
Looking at iPhones, Admob found that the iPhone 3GS captured 39% of iPhone OS requests, followed by the 2nd
generation iPod touch (25%) and the iPhone 3G (20%).
In a head-to-head device competition, the iPhone (22.2%) and iPod Touch (14.7%) dominated at the worldwide ad-request level, with the Moto Droid (4.0%) a distant third. Refine that report to smartphones only, and the Droid moves up to Number 2 (8.2%) behind the iPhone (45.5%). The report does similar breakdowns for the USA, UK, Indonesia, Philippines, India, and South Africa.
Download the full report here.