Sprint escalates mobile war with free year of unlimited service for switchers and up to 5 lines

The U.S. market for wireless services has grown increasingly cutthroat in recent months, but Sprint just went nuclear. In a quiet kind of way.

The nation’s fourth-largest mobile network operator seems to have launched a limited-time promotion offering a year of “unlimited” talk, text and data to users who switch from Verizon, AT&T or T-Mobile. The deal is available through June 30 for up to five lines for users who bring their own handsets and SIM cards, and Sprint isn’t charging an activation fee.

Like most other unlimited plans and promotions, some strings are attached: Autopay is required, hotspot data is limited to 10 GB a month per line, and the rebate is applied after two monthly invoices. Also, subscribers who sign on are eligible for a new Sprint phone after Oct. 1 of this year; those who upgrade before that date lose their free service plan.

Sprint executives said the carrier isn’t planning to market the promotion aggressively, but instead hopes to lure new customers without spending vast sums on ad campaigns.

“People are keeping their devices longer; this is really for us really a test for us – a toe in the water,” said Allan Samson, Sprint’s senior vice president of acquisition marketing. “Is there a way for us to reach these customers below the line, with a very low acquisition cost?”

And while capacity has become a major concern in the new era of unlimited data, Sprint isn't worried that the new promotion could result in a congested network.

“Once you have capacity, once you have inventory, you need lots of customers to fill it up,” said Samson, citing the carrier’s significant spectrum holdings. “We have no concerns at all…. Economically, we think this makes a tremendous amount of sense for us.”

Still, the offer is a blockbuster promotion that raises the stakes in a market that is already white-hot. Sprint claims the offer would save a customer $2,160 in a single year when switching four lines from Verizon.

“Sprint has just announced what is arguably the most aggressive promotion in the history of the U.S. wireless industry,” Craig Moffett of MoffettNathanson said in a research note. “Practically speaking, depending on how much the company promotes this, it’s fully possible that only a small number of gross adds will be captured through this plan given the planned short duration of the promo, though it could certainly be extended, as with other Sprint promos. Nevertheless, the signal is stark. And if word gets out—and how could one imagine that it wouldn’t?—customers could sign up in droves.”

This story was updated June 13 to add comments from Sprint executives.