NEW DELHI: Vodafone has launched an offer termed ‘ Double Data ’ for pre-paid customers in Mumbai , effectively halving data rates in the lucrative circle which contributes maximum revenue to India’s No. 2 carrier.Consumers availing data recharge via 121 or through the special offers section on the Vodafone website and MyVodafone app, will enjoy double the value of the chosen data pack, the telco said in a statement.This offer is valid on all Vodafone pre-paid data recharge packs offered in Mumbai starting first week of August. The offer came on a day Bharti Airtel announced the commercial launch of its 4G services across 296 cities and towns in India at 3G prices. With 4.8 million data users, out of a total subscriber base of 8.4 million in Mumbai, Vodafone India has seen overall data surge growing to more than 50% in the last one year. The telco has the largest revenue share with 32% in Mumbai among mobile services providers.