Asymco

comScore reported that 15.4 million iPhones were in use in the US as of November. (25% share of 61.5 million total smartphones.)

We also know that about 75 million iPhones were sold by November since the product launched. With about 17 million units older than two years, and assuming that half of those might still be in use and that all the iPhones less than 2 years old are still in use, we get an upper bound of 66.5 million iPhones in use globally.

That means 23% of all iPhones are in use in the US and that 77% are in use outside the US.

Can this be verified?

Chief Executive Philipp Humm said in an interview that many of his smartphones will eventually be made up of Google-powered phones costing less than $100, half as much as the smartphones typically available at U.S. carriers. In October, to lower the cost of monthly bills, Mr. Humm introduced a limited data plan that costs $10.

via T-Mobile Smartphones to Head Down Market – WSJ.com.

T-Mobile seems to be attempting to differentiate on price. In a regular market reaching saturation that might be a viable strategy. However the market is neither regular not saturated. T-Mobile’s chances of gaining large share are limited.