Horace Dediu of Asymco, estimates that T-Mobile could sell around 3.4 million iPhones this year, totaling 10% of their total subscriber base. This might have seemed like a stretch just a few days ago, but with the US-based company's new "UNcarrier" initiative, this could be an easy estimate to beat.
Dediu's estimates are based off trends from AT&T, Verizon and Spring, as well as the percentage of total subscribers that each operator has been activating. The Asymco analyst notes that the sales patterns are consistent across all of the carriers, and that the longer Apple's iPhone is available, the higher the activation rate.
The analyst also estimates that iPhone sales across the top four US carriers will break through 53 million in 2013, which will account for 17% of the 320 million subscribers, an increase of 14% year-over-year.