Amazon.com last night reported stronger than expected earnings as North American sales surged during the crucial Christmas quarter, sending its shares up 9%.
The online commerce giant, which gets about a third of its revenue from October to December, reported earnings of 45 cents a share.
This was much better than Wall Street's average prediction for 17 cents.
Revenue climbed 15% to $29.3 billion in the quarter, compared to an average analyst estimate of nearly $30 billion.
The sharply higher profit was a welcome surprise for Wall Street, which has clamoured for Amazon to come to grips with its growing investments in everything from Hollywood-style television productions, and cloud computing and consumer devices with mixed success.
In a conference call with reporters, its chief financial officer Tom Szkutak said Amazon is putting "a lot more energy around making sure we get great productivity around our various fixed and variable assets."
Even so, few analysts expect chief executive officer Jeff Bezos will rein in his spending significantly this year, especially as Amazon beefs up its $99-a-year Prime membership programme.
This offers standard two-day shipping, streaming video and unlimited photo storage among other perks.
Worldwide, paying Prime membership rose 53% in 2014, and 50% in the US market. In 2014, Amazon paid billions for Prime shipping and put $1.3 billion into its Prime video service, Bezos said in a statement.
The company said its net sales leapt 22% in North America, compared to 3% for everywhere else. Overall operating expenses rose 14.6% in the quarter to $28.7 billion.
Net shipping costs represented 4.6% of worldwide net sales, slightly lower than the previous four quarters.
