Now playing: Watch this: Try out an iPhone 5S for free with T-Mobile Test Drive



SEATTLE--T-Mobile is daring consumers to give its wireless service a whirl.

The nation's fourth-largest wireless carrier by subscriber on Wednesday unveiled a new program, dubbed "Test Drive," that would give people a week to test out its service for free. It is working with Apple to supply a pool of iPhone 5S units for potential customers to try out.

Customers can sign up online and receive the iPhone 5S loaner a few days later. They need to submit their credit card information, but unless the smartphone is broken or missing, the card won't be charged.

Test Drive represents T-Mobile's latest initiative under its "Uncarrier" campaign, which has won over consumers with the company's ability to focus on and fix the most annoying traits of the wireless industry, all while needling its rivals. The strategy, championed by firebrand CEO John Legere, has paid off with a staggering return to customer growth and a boatload of buzz. He believes this next move will continue to shake up the industry.

"This will be an industry standard in two years," Legere said in an interview.

Just as early upgrades and the option to pay for a smartphone in monthly installments -- which T-Mobile pioneered -- has become a common in the industry, so too will this test drive option, he said.

"They'll come kicking and screaming, I'm sure," he said.

The latest Uncarrier effort comes as speculation swirls around a potential merger between T-Mobile and Sprint. Regulators, however, may be reluctant to approve such a deal, with programs such as T-Mobile's Test Drive serving as evidence of how having multiple aggressive competitors benefits in the industry.

Legere declined to talk about the merger aside from reiterating his belief that consolidation would help fuel his Uncarrier campaign.

Test Drive gives T-Mobile the opportunity to back up its claim to the nation's fastest wireless network. While it does offer a speedy connection, the quality of its service is best in larger cities, with coverage slowing down once outside of the major metropolitan areas.

Verizon Wireless and AT&T both boast wider coverage across the nation, an edge that T-Mobile is working to narrow with additional spectrum and a host of network upgrades.

Still, T-Mobile's past Uncarrier initiatives, which eliminated wireless service contracts, introduced an early upgrade program, removed international data roaming charges, and covered the early termination fees of customers from rival carriers, have yielded positive results. In the first quarter, T-Mobile added a net 2.4 million new customers, more than all of the other carriers combined.

Perhaps the offer of seven days with an iPhone 5S may be enough to get more consumers to give T-Mobile a chance. After the seven-day trial period, people can return the handset to a local T-Mobile store.

For Apple, getting loaner iPhone 5S units out through Test Drive gives even more consumers the ability to test out its highest-end smartphone. The iPhone 5S is a loaner that must be returned. If a person wants to sign up for the service after the trial period, they can purchase a new smartphone -- an iPhone 5S or another smartphone such as the HTC One M8 or Samsung Galaxy S5.

James Martin/CNET

T-Mobile isn't going to compete against its rivals when it comes to marketing, so it is instead turning to Test Drive to get people to try its service.

"All Americans should cheat on their carrier with a seven-night stand with T-Mobile," said Chief Marketing Officer Mike Sievert.

Despite having the iPhone for more than a year, Legere said the awareness of T-Mobile carrying Apple products remains low. This is a way to raise the profile of a T-Mobile iPhone for both Apple and T-Mobile, he said.

T-Mobile calls Test Drive "Uncarrier 5.0," but teased that "Uncarrier 6.0" is still yet to come at its press conference held here late Wednesday.