Amazon's strength, in my opinion, derives from their customer loyalty. They recently reached one million customers in what seems like record time. The startling fact is that forty percent of their business is repeat customers, that means that over 400,000 people come back to shop at their internet site again, and these numbers keep on growing. I think Amazon.com is a strong company that is here to stay.
Wait until they have to account for/ pay the shipping costs. They may be free to you, but AMZN has to pay ! Next quarter expect to see an increase in sales but a decrease in gross margin and net income. Gotta go and short some more. Good Luck.