T-Mobile wants to give you an iPhone

(CNN) -- You can keep them for only a week. But T-Mobile is handing out free iPhones, along with a trial run of its cellular service, in the latest in a string of unorthodox promotions for the No. 4 wireless carrier in the United States.

Through "T-Mobile Test Drive," curious consumers will get an iPhone 5S loaner and seven days of unlimited data to check out the service.

Starting Monday, people can sign up for the program online. If they're not impressed, they can drop the phone off at any T-Mobile store, at no charge.

People must give T-Mobile a valid credit card number to get a phone. If they return a cracked or water-damaged phone, they're billed $100. If they don't return the phone at all, they're billed $700, plus tax.

In trying to crack the Top Three, T-Mobile has taken on the mantel of "The Uncarrier" under the guidance of CEO John Legere, a nontraditional business executive if ever there was one. Witness his slightly off-color quote promoting the new deal:

"The way this industry forces Americans to buy wireless is completely, utterly broken. I'm here to tell you there's a better way," he said. "While the carriers ask you to buy blind, the Uncarrier gives you transparency. Our network kicks ass, and now people can experience for themselves what a data-strong network can do with T-Mobile Test Drive."

Since March 2013, T-Mobile has eliminated binding contracts andlaunched deals like Jump, which lets customers upgrade phones twice a year for a modest fee instead of once every two years.On Wednesday, the carrier also announced that it would let customers stream unlimited music via Pandora, Spotify and other services without it counting against their data plans.And that's in addition to Legere, known for sporting a pink T-Mobile t-shirt under a suit nearly every time he's in public, engaging in stunts like crashing AT&T's private concert for developers at the Consumer Electronics Show in January.

This newly aggressive push comes even as Sprint, the third-place U.S. carrier behind AT&T and Verizon, is reported to be working on a plan to buy out T-Mobile for as much as $20 billion.
In fairness, similar rumors have swirled for several years. If a deal does go down, it looks like T-Mobile is ready to keep thumbing its nose at Sprint and other rivals right up to the moment the papers are signed.