I agree, but it seems to be a fundamentally different scenario than other companies with sky high P/Es such as LNKD and FB. While LNKD and FB have yet to figure out how to monetize their product, AMZN has a relatively simple (and demonstrated) growth plan. I think many investors are simply betting that Amazon will be able to capture significantly more of the retail market, and/or new revenue streams from places like cloud services.