So, you know that old joke about the retailer who sells items below cost, but claims he'll make it up on volume? Well, Amazon's latest earnings report is kinda like that: Inc. (AMZN), the world’s largest Internet retailer, missed analysts’ fourth-quarter revenue estimates and reported a 57 percent decline in profit, dragged down by shipping costs and the money-losing Kindle Fire.

Sales rose 35 percent from the previous quarter to $17.4 billion, but that fell short of the $18.3 billion Wall Street consensus. Net income fell to $177 million, or 38 cents a share, down from $416 million and 91 cents in the year ago quarter. That actually beat analysts consensus projection of 16 cents a share.

But perhaps what most disappointed Wall Street was the soft guidance for the current quarter, which came in at between $12 billion and $13.4 billion in sales, and a possible quarterly loss, compared to the $13.4 billion to $14.9 billion analysts had been projecting. Shares fell about 10 percent in after-hours trading.

As for the Kindle, Amazon says it sold 177 percent more units than in the previous holiday quarter, but once again didn't release any actual numbers. That's a healthy increase, but I'm wondering if it's as healthy as most observers expected?

In any case, Amazon CEO Jeff Bezos doesn't seem to be too worried about slim margins or quarterly results, instead choosing to sacrifice short term profits as part of a long term strategy. Time will tell.