T-Mobile USA (NASDAQ:TMUS) had a successful debut on the New York Stock Exchange on Wednesday. 

Investors bought into the company that consists of the merged T-Mobile and smaller MetroPCS. Deutsche Telekom (OTC:DTEGY) will retain a 74% stake in the combined company.

It's good timing. A pair of bidders are making a play for Sprint Nextel (NYSE:S), and the market can always use a third public player to keep AT&T (NYSE:T) and Verizon (NYSE:VZ) honest.

T-Mobile USA is losing contract subscribers, and its 43 million combined subscribers is less than Sprint's 55 million. It's also naturally a lot smaller than market leaders AT&T and Verizon Wireless. However, having a company check in every three months is important, even if T-Mobile's financials will be as unimpressive as Sprint's reports have been lately. 

In this video, longtime Fool contributor Rick Munarriz explains why it's important to have a third publicly traded wireless carrier for investors to dissect.