Flipkart's ex-CEO makes startling revelation. Pictured: Flipkart acquires mobile payments startup PhonePe. In Picture: The logo of India's largest online marketplace Flipkart is seen on a building in Bengaluru, India, Apr. 22, 2015.Reuters File

Mark the dates 13-17 October as two of the India's biggest online retailers -- Flipkart and Amazon -- take on each other. And it is certainly the customer who stands to benefit from the big fight.

Flipkart has announced its Big Billion Day sale starting 13 October till 17. Exciting offers across 70 product categories will be up for customers in the app-only shopping event.

It may be noted that the Indian major online retailer received flak on its first Big Billion Days sale last year after customers complained of cheating on discount, wrong prices, site crashes and several other problems. The company seems to be ready to take it up again, and this time it will run for five days unlike last year's daylong affair.

Myntra, which is more like Flipkart's sister company with the e-commerce giant owning major stake, will also be a part of the Big Billion Day sale, though only on select items.

Meanwhile, Amazon has also announced its Great Indian Festive Sale. Interestingly, the date falls between 13 and 17 October, which means it will take on rival Flipkart in the market. The company had organised Diwali Dhamaka sale last year, but it received more flak than praises from customers.

Unlike Flipkart's Big Billion Day, which is an app-only shopping event, Amazon India will allow customers access the deal on the web as well. However, it has some special deals for app users like privilege to access the deals 15 minutes before it hits the website and 15% additional cashback for HDFC card users.

Indian customers are likely to benefit from the Big Billion Day and Great Indian Festive sales. Since it will run for five days, the rush won't be as much as in case of one-day event. However, there are still chances of losing out on the items you want or not getting the right size if you are late.

Here are some tips to buy the desired items:

  • Good items are more likely to run out of stock, so log in early
  • Download the app in advance if you haven't
  • Access Amazon India's offer through its app as its users
  • Sign up and make sure that details like name, address and payment details are correct