Google's Android Market has only generated 7 percent of the gross revenues made by Apple's App Store since both stores launched, according to figures from investment bank and asset management firm Piper Jaffray and reported by AppleInsider.

Piper Jaffray's Gene Munster said around US$330 million has been generated on Android Market since it went live despite just 1.3 percent of applications being paid. Around 6.75 billion apps have so far been downloaded from Android Market, meaning 90 million were paid apps. Apple in contrast is estimated to have generated US$4.9 billion in gross sales since it started, with a much more significant 14 percent of downloads being paid.

The Piper Jaffray figures suggest Android users pay more for individual applications but download fewer overall. The top 50 Android apps have an average price of US$3.79 while the average on Apple’s App Store is US$2.01. Android devices typically have 34 apps compared to 71 on iOS devices.

Apple’s iOS is believed to take about 90 percent of all dollars spent on mobile devices, making it a more attractive platform than Android for developers. This is despite the number of apps on each platform being more closely matched, with Android Market having more than 300,000 apps compared to App Store’s 500,000.

Munster wrote in an investor note that although Google’s app store is likely to close the gap in terms of smartphone market share, Apple will continue to maintain a 70 percent share of mobile app dollars spent over the next three to four years.