SAN FRANCISCO -- The economy is finally catching up with Amazon ( AMZN). Even though the online retailer edged past Wall Street earnings estimates for the third quarter, it provided a wider-than-usual range for its fourth-quarter revenue guidance to account for further shifts in the economy. "All companies have limited visibility right now and we're no different," said financial chief Tom Szkutak, during a conference call with analysts. For the fourth quarter, Amazon expects revenue in the range of $6 billion and $7 billion. That was shy of Wall Street estimates for $7.05 billion. The cautious outlook sent the company's shares plummeting 13.8% to $43.10 in after-hours trading. That marked a 57% decline from their 52-week high. Amazon's stock price has gotten hammered in recent days on fears of a slowdown in consumer spending. The company posted a 48% increase in profit, climbing to $118 million in the third quarter, or 27 cents a share, from $80 million, or 19 cents share, a year ago. The results include a benefit of $15 million related to net foreign currency remeasurements. Analysts surveyed by Thomson Reuters had predicted earnings of 25 cents a share. Amazon's sales in the third quarter were up 31% to $4.26 billion, coming in at the low end of the company's guidance, and falling short of Wall Street estimates of $4.28 billion. Excluding the $80 million favorable impact from year-over-year changes in foreign-exchange rates throughout the quarter, sales grew 28% compared with a year ago.