NEW DELHI: About 85% of customers using Reliance Jio during its free offer period will continue to use it even after the Mukesh Ambani-owned telco starts charging for data services from April 1, though most of them would use it as a secondary connection, a survey by Bank of America Merrill Lynch has shown.About 67% said they would use Jio as a secondary SIM, while 18% said it would be their primary connection. Also, about 57% of those willing to stick with Jio said that they will go for its Rs400-500 package rather than the cheapest one, the survey said.The survey showed that Bharti Airtel had the most satisfied customers, at 97.7%, against 89% for smaller telcos. Only 17% of Bharti Airtel customers were the least interested in Jio as a primary SIM if the quality was good, while it was 41% for smaller telcos.Smaller telcos like Reliance Communications are the most vulnerable as most of their connections are secondary for their customers, who may shift to Jio, BoFA-ML said. About 24% of the respondents said they have not tested Jio. The biggest barrier (around 40%) for them appeared to be handset incompatibility or the need to upgrade their phones, while long queues were the second-most widely cited reason (31%). About 27% of them said they were satisfied with the current operator. The survey said that Jio’s free service was gaining reasonable traction with 26% respondents using Jio as primary SIM and 21% as secondary SIM. BofAML commissioned Survey Monkey to conduct an online survey of 1,000+ respondents across the country with 500+ Jio users. The sample had a 47%/53% female/male mix, with 38% in the 18-29 years age bracket, 40% aged 30-44 years, 14% aged 45-59 years and 7% in the 60+ years age group.The brokerage’s September survey demonstrated a high willingness among consumers to try out the Jio SIM. In the latest survey, too, over 75% were either using Jio or have tested it on someone else’s connection – up from 39% in September.“Interestingly, 26% users use Jio as primary SIM, which we think is more a reflection of constraints of the current handsets that have 4G only in the primary SIM slot. Over 5% consumers have used Jio dongles,” the survey found.About 55% of those surveyed find Jio speeds higher than of other telcos. Over a third agreed that speeds were faster, but inconsistent. Just over 10% believed Jio’s data services to be at par or inferior with other operators'. While over 44% said the speed has slowed over the last few months, a majority felt the speed is either adequate or improving.