T-Mobile's latest moves put other carriers on notice, go after whole new market

According to Entner, about one third of what businesses pay for wireless usage is overseas use, "so the savings with T-Mobile can be quite substantial."

What's more, the analyst said the offer targets immigrants who might leave the country regularly and more affluent customers who take trips abroad more frequently. While users who don't fall in these camps may not flock to T-Mobile's new offers, there is still plenty of growth potential with these other groups.

It's not all roses

Not everything about T-Mobile's new offers are perfectly peachy. International data speeds will top out at about 128 kilobits a second, meaning viewing an email with a large attachment or visiting a graphics-heavy site will be a challenge.

Henderek speculated T-Mobile struck deals with international roaming partners to use low-speed data at a cheaper rate. This, he said, creates a win for partners because the data wasn't being used by travelers who may have preferred turning off their phones to incurring enormous roaming fees.

Throw in the data speed boost packages and international partners are seeing yet more new revenue.

Henderek did call out T-Mobile's new Stateside International Talk & Text plan, which for $10 a month has the same $0.20/minute call rate (including mobile-to-mobile) to qualifying countries plus unlimited texting and unlimited landline calls in more than 70 countries for no extra charge.

"Looking at the US market, there are all sorts of VoIP service providers - Skype, Viber, etc. - that offer cheap and free long distance calls," he said.

"The package looks really good when compared to other carrier packages, and you can call someone with a regular phone service and not have to worry about that person having the same app as you. There is definitely a convenience factor, but the international long distance side of things is not really a big a deal as it would have been a few years ago."

We've asked AT&T, Verizon and Sprint to comment for this story and will update if we hear anything back.

Michelle Fitzsimmons

Michelle was previously a news editor at TechRadar, leading consumer tech news and reviews. Michelle is now a Content Strategist at Facebook.  A versatile, highly effective content writer and skilled editor with a keen eye for detail, Michelle is a collaborative problem solver and covered everything from smartwatches and microprocessors to VR and self-driving cars.