According to AdMob’s April 2010 Mobile Metrics Report, the number of iPhone OS devices in the US outnumber the amount of Android devices by a ratio of 2:1. AdMob estimates that for all of the 8.7 million Android smartphones in the US, there are 10.7 million iPhones and 18.3 million iPads and iPod touches. Worldwide, AdMob reports that there are 11.6 million Android devices compared to 27.4 million iPhones and 13.4 million iPads and iPod touches.Â Perhaps the most interesting facet of AdMobs report is just where the distribution of each OS is most prevalent. 75% of Android devices are found in North America, compared to 12% in Asia and 11% in Western Europe. The iPhone proved to be most popular in North America with 49%, followed by Western Europe at 28% and Asia at 14%.Â Switching gears, the largest number of ad requests the world over came from iPhone OS devices with 42%, down from 46% last month. Android stood still at 25%, while Symbian and RIM took up the third and fourth positions with 2% and 1% gains. In the United States, Android bested the iPhone OS for the second time having not moved from its 46% share. iPhone OS traffic dropped to 38%, while third place RIM gained 2% with a total of 7%. Palm’s webOS held firm at 3%.