Indian mobile operator Reliance Jio not only extended the deadline for signing up to its Prime membership by two weeks, the 4G newcomer announced a summer special giving users an additional three months of free service.

Mukesh Ambani, chairman of Reliance Industries (pictured), said Jio was deluged by millions of customers queuing up to purchase its new tariff plans, so it extended the offer. He also announced the Jio Summer Surprise, which gives Prime members who make their first paid recharge prior to 15 April services for the initial three months on a complimentary basis.

“The Jio Summer Surprise will be the first of many surprises for Prime members,” said Ambani, noting 72 million subscribers enrolled in the plan in just over five weeks.

In late February, when it announced it would begin to charge for data Jio launched Prime membership, which costs INR99 ($1.48) and offers unlimited data and free voice for a year for INR303 a month.

The new three-month free offer will certainly draw criticism from rivals Vodafone India and Idea Cellular, which filed complaints with the telecoms regulator and competition agency after questioning the validity of Jio’s first extension of free data offers in December 2016.

The Cellular Operators Association of India (COAI) noted lower pricing is generally good for consumers, the larger question of whether such pricing conforms to tariff regulations is a matter that needs to be settled by the courts and the telecom tribunal, The Economic Times (ET) reported.

COAI director general Rajan Mathews told the ET “the industry will continue to bleed under this pricing, and there is the risk of cascading impact on the banks, government and equipment manufacturers”.

Ambani said Jio invested INR2 trillion ($15.3 billion) in its network and already deployed 100,000 mobile towers and plans to add another 100,000 sites this year.