U.S. telco claims a family of four can save more than $2,000 compared to Verizon.

Sprint this week took a leaf out of Reliance Jio Infocomm’s playbook, by offering new customers 12 months of free unlimited voice, messaging and data services.

According to Sprint, a customer who subscribes to a single line will save $900 compared to someone who signs up to Verizon’s unlimited tariff. A family of four will save up to $2,160, the U.S. telco said.

"Sprint has just announced what is arguably the most aggressive promotion in the history of the U.S. wireless industry," said Craig Moffett, analyst at MoffettNathanson, in an Investor’s Business Daily report.

He suggested that Sprint might be having a weak quarter, and has resorted to this special offer in a desperate attempt to boost customer additions.

To be eligible, customers must have their own, unlocked smartphone, and be a customer of either AT&T, T-Mobile US, or Verizon. Customers must also opt for paperless billing, and sign up to automatic bill payment.

A $1.99 admin fee, a $0.40 regulatory fee, and other taxes and fees still apply. A $30 activation fee will appear on the first bill, but will then be credited within two billing cycles. The usual fair usage policy applies, and customers are limited to 10 GB per month of hotspot data.

After the year is up, the plan will cost $60 per month for the first line, $40 per month for the second line, and $30 per month for lines three to five.

The promotion is available until the end of June.

"We imagine this will likely trigger a response from the rest of the industry. And it won’t be pretty," Moffett said.

Sprint’s offer is reminiscent of Indian newcomer Reliance Jio Infocomm, which made headlines – and sparked a fierce price war – by offering free nationwide voice, messaging and 4G data between early September 2016 and the end of March.

Both are operating in increasingly-competitive mobile markets, as players adopt aggressive pricing tactics in a bid to win customers from one another.

The similarities end there though.

Jio is backed by India’s richest man, Mukesh Ambani, and can absorb the financial hit that comes with such a high-profile special offer. Sprint on the other hand has a mountain of debt and is scrambling to turnaround its business with a concerted cost-cutting effort.