iPhone Approaches 10% of U.S. Installed Mobile Phone Base

comScore today released the results of its latest survey of mobile phone usage in the United States, revealing that Apple is quickly approaching a 10% share of the U.S. mobile phone market. Among the top mobile phone manufacturers, Apple led the pack in growth between the three-month period ending in May and the period ending in August, growing by 1.1 percentage point to hit 9.8% of the U.S. market.

Looking specifically at smartphones and measuring platforms instead of manufacturers, Apple checked in at 27.3% of the market, up 0.7% over the prior period but trailing Android's 5.6 percentage point growth.

The reports also highlight the rapid deterioration in Research in Motion's market share. Apple and RIM had been neck and neck in share just four reports ago, covering the February-April 2011 period, but RIM has fallen to under 20% of the smartphone market as Apple has surpassed 27%.

comScore's surveys track installed user base rather than recent sales as tracked by many other firms. As a result, comScore's numbers react more slowly to changing trends in mobile phone sales than shorter-range measures of recent sales. But comScore's numbers would be more accurate reflections of actual consumer usage given typical upgrade cycles on the order of 18 months for average users.