According to data from Internet analytics firm comScoreData, Amazon India had 23.6 million unique visitors in May, edging past Flipkart narrowly.
While Flipkart saw 23.5 million unique visitors, Snapdeal had 17.9 million in May this year. An annual comparison shows that Amazon has seen over a 142 per cent jump in the number of unique visitors since May 2014 while for Flipkart, it's nearly 80 per cent surge.
For the same period, Snapdeal saw a 90 per cent rise in unique visitors, the data revealed. Interestingly, last year in May, Flipkart was leading by a mile, with more than 13 million unique visitors while both Amazon and Snapdeal were in a tight race with close to 10 million unique visitors to their sites.
When contacted, Amazon India declined to comment though it said the repeat rate of customers was "healthy".
Industry experts caution that unique visitors are just another metric for e-commerce companies, and the 'loyalty and stickiness' of customers are a more reliable measure to go by.
"While unique visitors is a metric to show the growing interest in e-commerce, a better metric to speak about a company's performance would be the number of repeat customers an online retailer gets," Arvind Singhal, chairman of retail consultancy Technopak, told PTI.
For a customer, online retail offers price comparison and available options by 'just a click', he said, and the market is still nascent to speak about customer loyalty, which is a significant aspect of offline retail.
Another popular parameter e-commerce companies quote is the gross merchandise value (GMV) to indicate the total sales value reflecting the volume of their business, Singhal said.
Currently, Flipkart, the country's highest valued e-commerce company, has said it expects its GMV to touch Rs 76,000 crore in a year.
Earlier, the company had said it expects to reach a GMV of USD 8 billion (over Rs 50,000 crore) by December. Snapdeal is also reported to be targeting GMV sales of USD 10 billion (about Rs 63,000 crore) by the end of calendar year.
While Amazon India does not share details of its sales, it's offering more than 25 million products for sale through its online marketplace.
It reportedly crossed USD 1 billion (Rs 6,300 crore) in sales in September last year while Flipkart reported a GMV of USD 3 billion for FY15.
Snapdeal reportedly crossed the USD 3.5 billion mark by May. "GMV is an important metric as far as size and scale of the company is concerned in e-commerce, but it is not the sole metric to gauge the health of business," Singhal said.
"In a marketplace model, the revenues for an e-retailer, which are a small margin of the sales, should also be taken into account," he added.