Wal Mart's profit margins are only a few percentage points, maybe 5% if they're lucky. That's the nature of retail. There definitely seems to be some utility and efficiency gains being made by Amazon. I doubt investors are seeking the kind of explosive growth or profits seen in tech companies like Apple, but rather a steady gain in market share from companies like Wal Mart, Best Buy, and whatever else you can deliver to a home.

Hmmm I wouldn't normally say a P/E of 272.63 is a bet on slow steady growth.

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.

Are you writing this comment from 2008? Both LNKD and FB have robust revenue streams that are growing; they have figured out how to monetize their products and they are doing it quite well.

Why, because of the large amount of reinvestment that makes E trend towards zero? How does P/E signal anything about a growth strategy?

Not quite, their operating income steadily grew until 2010, when it was about 5x higher than in 2003. That said, it makes sense. Amazon has very lofty but realistic goals, which are an intriguing combination. These goals would be impossible without all that investment.