Mobile advertising network AdMob's latest figures show that more than half of the ad requests from iPhones and Android handsets come from applications, rather than their browsers.

Meanwhile, AdMob says that both platforms continue to outpace the rest of the mobile market, with ad requests from Android phones increasing an average of 47 per cent every month in the five months following Android Market's launch last November.

However, iPhone is still top dog when it comes to ad requests on AdMob's network, generating eight times more requests in the US during March than Android.

Worldwide, that disparity increases to 23 times, although that includes iPod touch in the iPhone figure.

Meanwhile, the T-Mobile G1 generated 72 million ad requests during March, giving it a 2 per cent share of the overall US market.

The full report can be downloaded from AdMob's new Metrics blog.