Greystripe has dissected the usage patterns of 600 free, ad-supported iPhone applications in its ad network to come to a number of conclusions about consumers habits on the iPhone. Generally, it found that while usage may be intense, applications have a limited lifespan.

Here are the findings:

—Time spent per iPhone app session: an average of 9.6 minutes.
—Total number of times applications are accessed: 19.9 times before consumers stop using them.
—Users with household incomes above $165,000: 15 percent.
—Gender breakdown: 52 percent male and 48 percent female.

Greystripe’s apps—many of which are games—are mostly used in the U.S., followed by Great Britain, Canada, Australia, France, Singapore, Japan, Hong Kong, Mexico and Germany. The full report can be found here.