Sprint's own chart undermines its latest promotion, which shows the real strength of T-Mobile right now.

I'm Canadian; I have no skin in this game. Up here, we pay far more than anyone in the U.S. for far less. In Canada, the closest we come to 'unlimited' is bottomless breadsticks at Olive Garden.

We're now in this strange situation where T-Mobile is setting the tone and pace for the rest of the industry.

Which is why it's been fascinating watching the disruptive T-Mobile, which has double the subscribers of the entire population of Canada, almost singlehandedly upend the U.S. wireless industry, causing monumental shifts in the way customers use and consume wireless data.

On the one hand, the push to unlimited is a good thing; customers don't have to think about policing themselves — the vast majority of people can just pick up and use a phone without distinguishing whether it's on LTE or Wi-Fi. The downside there, though, is that unlimited comes at the expense of additional fine print; while one can technically continue slurping up as much data as he or she wants, after a predetermined amount — between 22GB and 28GB, depending on the carrier — traffic gets "deprioritized."

T-Mobile began this trend two and a half years ago (simpler times, simpler times) with Music Freedom, which, for Simple Choice customers on particular plans, didn't count a number of music streaming services towards one's data bucket. Back then, unlimited was just a glint in T-Mobile's eye, its network not yet able to keep up with the growing demand of a hungry population. But by the end of 2015, T-Mobile's network, having launched 700Mhz service and refarmed enough of MetroPCS's own spectrum, felt ready to move to video, launching Binge On.

In the proceeding months, Binge On was met with enormous amounts of criticism from all sides: net neutrality defenders believed it was contravening the very ideals of treating all internet traffic the same; consumer protection groups like the EFF were upset that T-Mobile was throttling all video traffic, not just services signed up for Binge On; and consumers themselves found the service confusing and difficult to disable. These issues were all addressed in due time, with John Legere himself bearing the brunt of the concern, but in the ensuing 18 months saw T-Mobile steal millions of customers from Verizon, AT&T and Sprint, leading to some of the best metrics we've seen from a U.S. carrier in years.

So now we're in this strange situation where T-Mobile, the third-largest carrier in the U.S., is setting the tone and pace for the rest of the industry, genuinely affecting the bottom lines of the incumbents, AT&T and Verizon. What was a single fly buzzing around making noise just a couple of years ago is now a swarm that the top carriers can no longer ignore.

Which brings us to this chart. Sprint, the embattled fourth carrier, is still making amends for its decision to invest in WiMax all those years ago, and has neither the coverage nor the balance sheet to make a run for T-Mobile. Its latest act of desperation is a salvo worthy of a surrounded army: offer five lines for the cost of two in the hopes that entire families — the true money makers — will switch over. But Sprint's deal is hobbled by the fact that it's for new customers only, and that the promotional price will revert to its far more expensive regular cost in just over a year.

This isn't to say that Sprint's deal is a bad one; unlike AT&T's newly-expanded unlimited plan, it does include tethering and HD video streaming, but Sprint's network is neither as robust nor its devices as transferrable as T-Mobile's.

At the end of the day, though, unlimited is just another buzzword for a handful of networks that are now technically able to eke sizeable profits without crumbling under the weight of America's lust for video. And that's a good thing for everyone.

Which unlimited plan should you buy: T-Mobile, AT&T, Sprint, or Verizon?