Is T-Mobile finally relevant?

T-Mobile isn’t the biggest carrier in America, but it is quickly becoming the most important. The company struggled for years to compete with Verizon Wireless and AT&T, but now T-Mobile is finally gaining traction thanks to CEO John Legere’s big personality and his team’s even bigger ideas — ideas that are forcing the market leaders to do what they have always tried to avoid: change. The executive on Wednesday unveiled the third stage of his “Uncarrier” initiative, which so far has helped T-Mobile to not just slow subscriber bleeding but actually add branded subscribers for the first time in years. How are Legere and company turning things around? With some slick marketing and even slicker strategic shifts that dare to go where AT&T and Verizon have historically feared to tread.