T-Mobile’s merger with AT&T might be nixed by the justice department, but that might be the least of the carrier’s worries. Currently at 33.6 million customers, they’ve been losing out to other brands during the past half year.

The fourth largest carrier in the U.S. has had to endure the image that it’s unable to compete at the highest level with companies like Verizon Wireless and AT&T. At the same time, they’re seen as not as thrifty as companies like Sprint Nextel and MetroPCS.

So T-Mobile sees its best sort of customers, those that buy smartphones and sign up for two-year contracts with expensive data plans, leaving. It’s not due to dissatisfaction on the whole (customers are more satisfied with T-Mobile than AT&T) but due to the fact that they don’t offer the iPhone like AT&T and Verizon.

T-Mobile has also had to suffer through the problem of limited wireless spectrum, as they’ve been slow to buy up space on the airwaves like the competition. The company’s own estimates believe that smartphone data use could fill up their airwaves in a few years.

Recon Analytics analyst Roger Entner thinks that Sprint has done much better by focusing on their customer service. “The U.S. market is competitive and companies can come back from near death when they do things right,” Entner said. “The problem is that T-Mobile USA’s parent Deutsche Telekom is not committed to the U.S. market the same way its competitors are.”

Source: AP