I knows amazon even before it came to in india, it is one of the first to sell online, it is an reputed which it has built down by its quality of delivering of goods, supplues& products are as committed.
The only issue lies with Cash in delivery, most of the time they will ask you for card, they denies or shows reluctance in collecting cash .
Another issue is if you anything on cash on delivery& somehow due damage or due any other issue product returns back you have to buy it again even you might have bought it on sale which can be unavilable next time.
Hence please be ready for bad experience if you are ordering fir COD