I was a regular customer of amazon.com since long, far ago than amazon came to India with amazon.in website. I used to purchase digital products like ebook and videos. As the digital products are downloadable you never have to worry about delivery time or delivery in proper address.
But as it is an international portal you should have a credit card to purchase your product. Moreover you will find the products costly. The same product when you purchase through their Indian portal, i.e it will be cheaper. This is because their conversion value from dollar to Indian Rupees is lower than what is presently there in the market.
I recommend not to purchase physical products from amazon.com because you will have to bear huge shipment cost. I don’t recommend amazon.com for Indian customers, better they try amazon.in