The iTunes App Store is the place to be at the moment for developers who are looking to monetize their mobile applications as a recent Distimo report shows that the iTunes App Store is dominated by paid app compared with amongst other Android Market.
The graph above illustrates the relative size of the different app stores and the breakdown between free and paid-for apps in each market. As we can see both the iPad app store and the iPhone app store is dominated by paid-for apps, and combined these two are about twice the size as the Android Market, which is growing fast but only recently started making it easier for developers to directly charging for their app through the store.
For Apple and developers it must be extra encouraging to see that there is a high degree of paid apps in the iPad app store, boding well for future earnings given the popularity of both the original iPad as well as the recent launch of the iPad 2.
In terms of number of applications this feels very much like a two horse race at the moment, but lets not forget that quantity does not out-duel quality, and Apple and Google can not rest on any laurels.
Question now is if there is any correlation between free vs paid app split in an app store and user / market maturity? The iTunes App Store has been around the longest, and in that sense has matured the most. Plus it has been under tight control by Apple since it was first launched, whilst the likes of Android Market was far from a finished product at launch but is starting to mature more now.