Amazon has been viewed as one of the winners of the 2009 Christmas season
Profits at online retail giant Amazon leapt by 71% in the last three months of 2009 as shoppers spent more than ever during the festive season.
Amazon reported a net profit of $384m (£238m), up from $225m in the same quarter a year ago.
Sales rose 42% to $9.5bn, helped by favourable changes in foreign exchange rates, the firm said.
Amazon founder and chief executive Jeff Bezos highlighted the popularity of its Kindle electronic book reader.
"Millions of people now own Kindles," he said. "And Kindle owners read, a lot. When we have both editions, we sell six Kindle books for every 10 physical books."
However he did not give any specific sales figures.
'No chinks in the armour'
For 2009 as a whole, Amazon's profit rose 40% to $902m.
Looking ahead, the firm said it expects sales in the first three months of the year to grow between 32% and 43% compared with the first quarter of 2009.
Amazon shares initially fell more than 7% in extended trading, before swinging 3% higher in a short period of time.
"So far I see no chinks in the armour of Amazon's earnings report," Frederick Moran, internet analyst at Benchmark, said.
Amazon also said its board had authorised it to buy back up to $2bn in common stock.
The company said that it repurchased its shares from time to time "when it believes that doing so would enhance long-term shareholder value".