T-Mobile US’s customer base jumped by 1.1 million in its financial Q2, with the iPhone – offered by the carrier for the first time back in April – accounting for 29 percent of sales.

The company had lost over 200,000 customers in the same quarter the previous year. The company’s turnaround is being attributed to a combination of its new approaches to contracts – Uncarrier (whose introduction was not without controversy) and Jump – and the decision to add the iPhone 5 to its handset range. Earlier research by CIRP had suggested that 300-400,000 customers would have left the carrier if it hadn’t introduced the iPhone … 

The company reported that the Samsung S4 also sold well, with smartphones accounting for 86 percent of its total handset sales, up from 71 percent the previous quarter.

The company’s financials were complicated by its acquisition of MetroPCS in May. While revenues climbed from $4.68B to $6.23B, much of this was from customers acquired from MetroPCS. Profits, however, fell, last year’s $107M profit turning into a $16M loss. This was attributed to promotional costs and initial subsidies on handsets which the company expects to recoup later in the year.