• by Thom Forbes  @tforbes, August 22, 2014

With T-Mobile firing back to a Sprint salvo earlier in the day, the No. 4 and No. 3 mobile carriers have now declared “unlimited” war on each other just weeks after their long–simmering plans to merge fell apart.

The day began with Sprint offering to individuals an industry-best unlimited data plan after unveiling a “20GB of Shared Data” plan for families on Monday. It now will offer unlimited talk, text and data for $60 to individuals who don’t need a subsidy to purchase a phone — whether they have a usable device already or are willing to pay full price for a new one. 

“Sprint is marketing the new plan as the cheapest around, beating T-Mobile, its only national competitor offering unlimited data by $20 a month,” writes CNet’s Marguerite Reardon. “AT&T and Verizon abandoned unlimited data plans more than two years ago.” 

Under the hed, “T-Mobile Urges Its Customers to Rescue Beleaguered Sprint Customers,” T-Mobile soon blasted back with a rabble-rousing press release.

“Starting next week, whenever a T-Mobile Simple Choice customer throws a lifeline to a Sprint (or AT&T or Verizon) customer and brings them to the Un-carrier, both receive unlimited LTE data for a full year on T-Mobile’s blazing-fast LTE network, at no additional charge,” it said, adding that existing customers who already have unlimited data would receive a $10 credit for 12 months.  

While naming T-Mobile “rival nine times and criticizing the speed of its network,” as Thomas Gryta reports in the Wall Street Journal, T-Mobile CEO John Legere also fired some buckshot. 

“It continues to amaze me to see the old carriers failing to listen to their customers, or reward them for their loyalty,” he said. “That arrogance and indifference has defined the U.S. wireless industry for too long. We're changing that.”

In characteristic style, Legere (@JohnLegere) also tweeted yesterday: “Apparently @sprint doesn't know who their competition is. @MetroPCS offers $60 unlimited incl taxes and fees! #whoops”. MetroPCS is a prepaid wireless service owned by T-Mobile US.

On Monday, Sprint said it would offer existing family customers 20 gigabytes of shared data for $160 — the same price as plans offered by Verizon and AT&T but with twice the data, reported the Wall Street Journal’s Ryan Knutson.

“The strategy is simple,” new Sprint CEO Marcelo Claure told Knutson at the time. “We have to get back in the game.”

Subscribers who switch from other carriers between today and Sept. 30 get the plan for $100 a month through 2015. 

“That price would cover up to 10 lines, meaning subscribers could also add tablets, a big source of growth for the major carriers,” Knutson pointed out, plus Sprint will rebate up to $350 of penalties incurred for switching and add 2GB of data per line.

Sprint also axed its heavily advertised “Framily” plans earlier this week “because it didn’t compare directly with rival prices,” Sprint CMO Jeff Hallock told Bloomberg’s Scott Moritz. 

“This is a simple, straightforward, affordable plan,” Hallock said. “There’s no gimmicks to this, it’s not a promotion, there are no hoops to jump through like T-Mobile’s where you have to figure out how to refer others.”

When it comes to pointing fingers, however, it’s tough to keep up with the digits flying out of Legere’s T-Mobile.

“In keeping with its snarky image, T-Mobile is marketing its promotion as a way for its customers to ‘rescue’ Sprint users,” blogs the Washington Post’s Brian Fung. “It looks like there's no love lost between the two companies. And that makes sense; the wireless market is so heavily saturated as to be a zero-sum game for post-paid customers at this point.”

So what about the other guys, you ask? The market leaders?

“Being more expensive has not hurt AT&T or Verizon so far,” points out Daniel Kline on Motley Fool. “If both companies can continue to grow without cutting prices (and profitability), there is no reason to respond to what their smaller competitors are doing.”

“Verizon, which doesn't offer an unlimited data option, responded to Sprint and T-Mobile's new plans by pointing out that its network was recently ranked the best in Los Angeles, in California and in the U.S. by RootMetrics, a network testing firm,” writes Salvador Rodriguez in the Los Angeles Times, who compares family plans from all four carriers here.

“Consumers make decisions on a variety of factors not just price,” Verizon spokesman Ken Muche told Rodriguez. “They want to know what their experience is going to be like on a network, and they're going to ask themselves, ‘Is this truly unlimited?’”

Wow. Good thing there’s a weekend ahead to ponder such imponderables.