Amazon.com says its fourth-quarter net income fell 45%, as higher revenue failed to keep pace with increased spending on order fulfilment and digital content.
The online giant said it earned 97 million dollars (£62 million), or 21 cents per share, in the October-December period.
That is down from 177 million dollars (£112 million), or 38 cents per share, in the same period a year earlier.
Revenue at the world's biggest online retailer grew 22% to 21.27 billion dollars (£13.5 billion) from 17.43 billion dollars (£11.06 billion).
FactSet says analysts had expected earnings of 28 cents per share on revenue of 22.26 billion dollars (£14.12 billion) .
For the current quarter, Amazon expects revenue of 15 billion dollars to 16.6 billion dollars (£9.5 billion to £10.5 billion). Analysts had expected revenue of 16.86 billion dollars.
Nonetheless, Amazon's stock is up 5% in after-hours trading in the heels of the announcement.