MUMBAI: In an attempt to encourage customers to sign-up for higher-priced tariff plans, Reliance Jio has increased its cashback offer to Rs 3,300 from Rs 2,599 for recharges of Rs 399 and above.Under latest offer launched on December 25, Mukesh Ambani's company said on recharges of Rs 399 and above, subscribers could get vouchers of up to Rs 400, instant cashback of up to Rs 300 in their mobile wallets and discount coupons worth as much as Rs 2,600 from e-commerce players.To avail the offer, subscribers need to recharge before January 15. The new plan comes just a month after the telco offered its previous cashback offer worth up to Rs 2,599. The Rs 399 plan has been the most popular for Jio in October.The company has reduced the validity of the plan to 74 days from 80 days. For validity of 80 days, it now charges Rs 459. According to analysts, till a year ago the sweet spot for quarterly average revenue per user (ARPU) was the Rs 250-260 range, but now operators want that spot to be in the Rs 350-plus range to improve their revenue. As of now, jio has 160 million subscribers.Telecom operators are offering cashback options in the higher tariff range to sustain their ARPU and encourage subscribers to use of mobile wallets, through which the money is returned. Bharti Airtel, Idea Cellular and Vodafone India have also announced their cashback options recently. Cashback offers help companies sign up new customers and keep the ARPU at least flat, if not increase it, for a few quarters.Jio’s July-September ARPU was Rs 154. Last Friday, the newest operator rolled out monthly tariff plans for Rs 199 and Rs 299, in which the subscriber gets Rs 1.2GB and 2GB a day of data, respectively.The industry has seen ARPU plummet almost 40% in the September quarter from a year earlier, when Jio started its initially services which were free in the initial months. Jio’s entry triggered a price war, making bundled voice and data offers the norm rather than the exception.