[tptacek]

Without getting into the specifics, we can think of the P/E both as a measure of how speculative the future earnings are (Amazon, which is consistently and deliberately barely profitable, reflects little of its upside in its earnings; Apple, on the other hand, is milking its cash cows for all they're worth); another way to think about it is, Amazon is plowing more of their earnings back into efforts to buy market share, where Apple is extracting them into cash reserves right now.

Remember, Apple's market cap is still much larger than that of Amazon. Even though Amazon has what over the long term might end up being a much more lucrative model, in that it is poised to more or less control retail and retail logistics everywhere.

They're both great companies, but the P/E of each company tells a different story about their business (neither story is bad).