Amazon (NASDAQ: AMZN) threw around a lot of big numbers in its fourth-quarter update last week. The biggest of the bunch was the company's revenue of $514 billion last year. Amazon generated annual sales greater than the market caps of all but eight members of the S&P 500.

But there was one metric that the company's management mentioned that is arguably the most important for investors. And I think that one number makes Amazon stock a no-brainer buy right now.

Image source: Getty Images.

Continue reading

Source Fool.com