When it comes to mobile advertising, the iPhone OS was most dominant in Australia, Singapore and Hong Kong with 93%, 84% and 76%, respectively, of ad requests in December 2009, according to AdMob (http://metrics.admob.com).

These three countries are responsible for 69% of the region’s total iPhone traffic. The Symbian OS lost 39%, 29% and 16% of ad requests in Australia, Singapore and Hong Kong, respectively.

AdMob stores and analyzes handset and operator data from every ad request in its network of more than 15,000 mobile web sites and applications to optimize ad serving. Each month, the AdMob Mobile Metrics Report aggregates this data to provide insights into major trends in the mobile ecosystem.