Amazon India has one of the best customer services. The best part is, they call you back on your number and you just need to press a button on your amazon app on your phone.
The website and app both are good but can be better by providing more filter options.
The delivery of the products are done withing the stipulated time, however many products have delivery time of more than 3 days by the sellers on the site.
Whether the product is sold by Amazon assinged sellers or othe sellers, it is reliable as we have the option to return the product in case we are not satisfied with the product.
The affiliate program is said to be good, but so far I have not been able to track or see my referral sales reflected in a proper fashion.
Of all the above, you can purchase the products at a lot cheaper cost duing the offers, and more discount on paying via specific credit/debit cards or Amazon Pay balance.