Image source: T-Mobile.

Over the past several years, T-Mobile (TMUS -0.99%) has successfully shaken up the domestic wireless industry through a series of "Un-carrier" initiatives intended to address individual customer pain points. The company continues to unveil new offers that appeal to a wide variety of consumer preferences, and T-Mobile continues to enjoy robust customer growth as a result. T-Mobile recently became the third largest wireless carrier in the U.S. thanks to its aggressive strategies.

CEO John Legere has been instrumental in this turnaround, as the brash CEO has no compunction about speaking his mind. He has been able to turn customer perception around the network as well by intelligently choosing a new streamlined network strategy around 4G LTE and investing heavily in spectrum. The carrier has also spent very heavily on marketing promotions, but these investments will pay off if it can retain all of the customers it is garnering.

As of the most recent quarter (ending Sept. 30, 2015), T-Mobile had 61.2 million customers.

Here's a breakdown of T-Mobile's customer base since 2013.

Quarter

Postpaid

Prepaid

Wholesale

Q1'13

20.1

6

7.8

Q2'13

20.8

14.9

8.3

Q3'13

21.4

15

8.6

Q4'13

22.2

15.1

9.3

Q1'14

23.6

15.5

9.9

Q2'14

24.5

15.6

10.4

Q3'14

25.9

16.1

10.9

Q4'14

27.2

16.3

11.5

Q1'15

28.3

16.4

12.1

Q2'15

29.3

16.6

13

Q3'15

30.4

17.2

13.7

Data source: SEC filings. Customer figures in millions.

T-Mobile's prepaid customer base grew significantly following the 2013 acquisition of MetroPCS, but T-Mobile has continued to make progress expanding in both the prepaid and postpaid market segments.