The revelation, which was all but buried in the company's quarterly earnings report, makes the G1 the dominant 3G device on T-Mobile's network , with two-thirds of its 3G customers toting the Google software-based device.

Although the G1 hasn't achieved the success of Apple's iPhone -- Apple sold one million iPhones in about two months and one million iPhone 3Gs over a single weekend -- T-Mobile's figures demonstrate a healthy market for mobile innovation. Still, analysts said good news for HTC, maker of the G1, and T-Mobile doesn't necessarily translate to a smash hit for Google -- at least not yet.

"When you compare Android to other platforms, it is younger and it is struggling right now to get the type of unit sales the Apple iPhone enjoys or the breadth of the devices Windows Mobile and RIM's Blackberry have. RIM sold eight million BlackBerries last quarter," said Avi Greengart, a wireless analyst for Current Analysis. "But we'll have to wait until later this year when more devices are developed for Android to see what happens."

Mobile Applications Grow

Despite Android's youth, there is no denying its growth. AdMob, a mobile advertising platform, is putting a spotlight on the rapid growth of both the Android and iPhone platforms in its March 2009 Mobile Metrics Report. The company said growth in requests from devices running the Android and iPhone operating systems continued to outpace other platforms in March, despite the relatively limited number of devices in the market.

AdMob concluded that the application stores for both platforms have significantly influenced this growth, spurring hope for online stores by Research in Motion, Microsoft and Nokia.

Specifically, more than half of Android and iPhone requests in March came from applications. In the first five months following the launch of the Android Market in the U.S., Android requests increased an average of 47 percent each month. By comparison, in the first five months following the launch of Apple's App Store in the U.S., requests from the iPhone increased an average of 88 percent per month.

Android's Rapid Ascent

Drilling down further into AdMob's metrics report, the HTC Dream (G1) generated 72 million requests, giving it a two percent share of the overall U.S. market in March. That month, the HTC Dream was the number 10 overall device and the number four smartphone, after the iPhone, BlackBerry Curve, and BlackBerry Pearl. The Android OS now has six percent of the U.S. smartphone market and is tied with Palm as the fourth-largest OS.

Still, the iPhone reigns. The iPhone generated eight times more U.S. requests than Android in March. The iPhone platform in total -- iPhone and iPod touch -- worldwide generated 23 times more requests than Android. The App Store has crossed the one billion download threshold.