Disproving reports that its growth days are behind it, Amazon.com Inc. (NASDAQ: AMZN) today reported quarterly results that far exceeded Wall Street estimates.

Net income at the No.1 e-tailer more than doubled to $158 million, or 37 cents a share, up from $78 million or 19 cents per share. Revenue jumped 41% to $4.06 billion. The New York Times noted that analysts had expected a 26 cent profit on sales of $3.96 billion. The results, though, were not good enough for Wall Street, and investors sent Amazon's shares tumbling in after-hours trading.

One reason for the thumbs down may be that the company's gross margins -- always a concern with investors -- contracted slightly. The company also maintained its revenue forecast for the current period. Maybe investors were expecting the company to boost earnings guidance as it benefits from shoppers bypassing malls and spending on gasoline in favor of shopping at home.

Skeptics, including me, have underestimated the company. Soleil Securities analyst Scott Tilghman told Bloomberg News that "There's a misperception out there that e-commerce is much more mature than it actually is. They (Amazon) offer one-stop shopping and often better prices than bricks-and-mortar stores, which should offset any slowdown in consumer spending."

Looks like he may have a point.

[July 24 UPDATE: Amazon shares soar after Chief Executive Jeff Bezos' bullish comments. The shares were little changed at first until Bezos said on the earnings conference call that the company was benefiting from consumers avoiding driving to brick-and-mortar stores because of concerns about high gas prices. Shares are up over 15% by early afternoon Thursday.]