According to a recent report released on Wednesday by Distimo, Apple’s App Store for iPhone has generated four times as much revenue than Google’s Android Market. Interestingly, there are more Android smartphone users than there are iPhone smartphone users. This perhaps highlights the higher quality of apps or rather a more powerful distribution channel that Apple possesses. Helping this growth however, is largely contributed by in-app purchases – users wanting to add that extra power-up or possess that oh-so special weapon are pushing revenue growth. Read more for colorful graphs.

Distimo illustrates the iPhone’s 4x revenue advantage over Android with the graph above. The iPad also makes a noteworthy mark by beating Android as well. These figures are from the 200 highest grossing apps for all three stores.

Revenue growth has been helped by the explosion of apps in all stores. The exhibit above depicts that astounding increase. Distimo provides further analysis and mentions that revenue from both camps have been driven largely by free-apps containing in-app purchases.

When you break down app growth by free-apps you’ll notice that both iPhone and Android stores have made some significant strides, especially Android. According to Distimo, approximately half of the revenue generated from apps in the Apple App Store originate from these free-apps. Even more amazingly is the Android Market where the number is 65%. Android has become the largest free-app market.

What are people downloading causing this drive in revenue? The answer is simple – Games. Games are the “most robust and thus the most important.” There are 79,077 games available for iPhone, 28,683 for the iPad, and 46,045 for the Android Market.

For more information on the report check this link.