In AdMob’s July 2009 monthly metrics report, a special section on iPhone, iPod Touch and Android app usage showed the results of a 1,000-person survey to find our more about their interaction and download behavior with apps.

A couple highlights:

• Android and iPhone users download approximately 10 new apps a month, while iPod touch owners download an average of 18 per month
• More than 90 percent of Android and iPhone OS users browse and search for apps directly on their mobile device instead of their computer
• Upgrading from the lite version was the top reason given when users were asked what drives them to purchase a paid app
• iPhone and iPod touch users are twice as likely to purchase paid apps than Android users.
• Users who regularly download paid apps spend approximately $9 on an average of five paid downloads per month

There is a supplemental presentation that includes all of the data from the surveys for those who are interested to dig into the details.