The iPhone may be the king of the app world, but Android-powered devices are rapidly gaining ground. A new report by mobile advertising company AdMob breaks down mobile app purchasing and usage by device -- and, if the results are to be believed, Android's app market is the underdog to watch when it comes to on-the-go program sales.

Mobile apps: Android vs. iPhone
The AdMob study actually indicates that Apple users are spending more app-related dough than their Android counterparts. The Apple App Store, AdMob says, sees twice as many paid app downloads per user as the Android Market. Researchers say this effect is because the majority of Android users simply don't download paid apps at this point; only about 19 percent of them are regular purchasers.

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Here's where things get interesting, though: When it comes to users who do download paid apps, the Android crowd is right on pace with the Apple gang. Both Android and iPhone users spend 80 to 90 minutes a day using their apps, AdMob finds, and -- perhaps most noteworthy -- active app-purchasers on Android and iPhone are neck-in-neck with the same average of five paid downloads, or $9 in app-related spending, each month.

App analysis
So why is that so significant? Right now, Android has a far smaller number of devices -- and, consequently, a far smaller pool of users. But it's showing tremendous growth, with a slew of new phones on the way: T-Mobile recently unveiled its Android-based myTouch 3G handset; Motorola is expected to release an Android phone next month; and both Verizon and AT&T are rumored to have new Android devices in the works.

In fact, one research firm goes as far as to predict a staggering 900 percent increase in Android adoption over the next year -- and that's accounting only for smartphone sales, not the wide range of other Android gadgets and gizmos also under development.

Considering that Android's active app users, according to AdMob, are buying the same number of monthly apps as Apple's, the real difference resides in the total number of active app-purchasers. Given the Android growth projections, then, one could see the potential for enormous gains when it comes to the platform's app sales in the coming months.

Does the App Store have reason to be cowering in the corner with fear? Of course not. (Sorry -- you're not getting any "[insert your favorite technology] killer" predictions from me.) For those of us who enjoy watching trends, though, this data is certainly something worth bookmarking.

JR Raphael shows his less serious side at eSarcasm, his new geek humor site. You can also catch him on Twitter: @jr_raphael.

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