As Internet penetration is increasing and e-commerce becoming more secure, the number of people transacting online is expected to touch 39 million by 2015, says a study.

According to the study by financial services firm Avendus, this will also provide a further fillip to the Indian e-commerce market which is estimated to grow to USD 24 billion by 2015 from USD 6.3 billion now.

At present, about 8-10 million people in India transact online, which is about 11 per cent of the 80 million Internet users in the country, which represents a penetration of seven per cent of the population and 17 per cent of the urban population, says the study titled 'Indian Digital Consumer Industry'.

The number of transacting users in the US was 170 million in 2010, comprising of 69 per cent of the overall Internet users there. This number has been growing at eight per cent for the last six years. In India, a large part of the transaction takes place on travel-related sites, it said.

"The number of unique users transacting on travel sites (only) are estimated to be around 6-7 million and for non-travel ecommerce sites is around 2-3 million today," it said. In India, online travel revenues are dominated by ticket bookings, with air and TRAIn bookings accounting for close to 90 per cent of the segment's revenues. Bus travel, hotels and tour packages have been slower to evolve but are now growing rapidly.

"The online travel market is estimated at Rs 24,900 crore (USD 5.5 billion) in 2011. This makes India one of the most lucrative markets for online travel," the study said.

While 57 per cent of the online travel revenue came from air travel, TRAIn and hotel packages contributes 37 per cent and five per cent, respectively, in 2010-11. The remaining one per cent was from bus bookings.

Online travel is expected to grow at 22 per cent to reach Rs 54,800 crore by 2015, it added. Online TRAIn ticket bookings are estimated to be around Rs 8,000 crore (USD 1.8 billion) in 2010-11, accounting for around 32 per cent of the overall ticket bookings.