Global e-commerce sales made through mobile devices are expected to cross $638 billion (roughly Rs. 40,56,161 crores) by 2018, says a joint study by Assocham and Deloitte.

At present, the availability of e-commerce applications on various mobility devices is helping to drive sales and revenue. Online retailers like Flipkart, Amazon and Jabong now get 50 percent of their revenues from consumers shopping on their mobile phones, D.S. Rawat, secretary general Assocham said.

However, while shoppers want real-time, relevant, and personalised information and offers, retailers will need to surround this service with very strong privacy and security. Trust, transparency, and protecting customer information will be critical in retaining loyalty as mobile retailing becomes the norm, the study said.

"Online commerce companies should enable all features from search-to-purchase on mobile apps, such as facilitating product research, price comparison, view ratings and reviews, and payment."

The launch of wearables, such as Google Glass and Apple Watch, has opened new opportunities for reaching out to customers, the study said, adding that online retailers would keep an eye on developments in this arena.

The online marketplaces are growing significantly with the increase in the Internet penetration and smartphone usage. Internet-enabled mobiles are making shopping a unique experience for buyers.

According to the joint study "Global Powers of Retailing 2015", online marketplaces rather than pure inventory-led companies tend to serve as the primary e-commerce model in Asia.

"The high costs of holding inventory, poor logistics and supply chain challenges in India are shifting the inventory-led companies and new entrants to adopt marketplace model," the study said.

It also said cash-on-delivery is the most preferred mode of payment in India with 45 percent of the shoppers using it, while 21 percent shoppers opt for debit cards and another 16 percent go for credit cards.