Here's a quick quiz to snap you out of that post-lunch lull: which of the following isn't like the others? a)Amazon, b)Apple, c)Microsoft, d)Google, e)Yahoo.

Think you've got it?

If you chose Amazon, give yourself a gold star. The company was the only one among the major tech heavyweights this quarter to beat Wall Street's expectations. Their quarterly net income doubled from a year ago, and total revenues hit more than $4 billion, they announced today.

So what's Amazon got that everyone else doesn't? The speculation is that the good news was the result of the sale of European DVD rental assets. But is that the whole story? For extra credit, share your take on things in the comments section below.

What's Amazon got that everyone else doesn't? Hazard your guesses below!