The App Store is one the most important reasons the iPhone is as successful as it is. Yet for all its success, it's a really tiny business for Apple.

The App Store has only kicked in 1% of Apple's overall profits since the App Store opened in June 2008, according to an analysis by Piper Jaffray's Gene Munster.

Apple app sales total $1.43 billion, with Apple getting 30%, or $429 million. After you factor out payment to the credit card companies and storage and delivery, Apple's gross profit is $189 million.

Apple's overall gross profit since the App Store launched is $33.7 billion.

This comparatively small profit is by design. The App Store was never supposed to be a big business. Its job is to sell more iPhones, iPod touches, and iPads. And so far, it's doing that spectacularly well.

Munster estimates 81% of apps downloaded are free, and the average price for a top-50 paid app is $1.49. Here's how the price of an app breaks out.

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