Amazon.com has posted a net income of $97m, or $0.21 per diluted share, for the fourth-quarter of 2012 compared to a net loss of $274m in the previous quarter.

Revenues grew by 22 per cent to $21.3bn, while online sales grew 14 per cent during the quarter.

Operating profit margin in North America grew by 5 per cent in fourth-quarter, while profit of international business declined.

Tom Szkutak, CFO of Amazon, said: “We will still be adding capacity during 2013.” Szkutak indicated that by constructing delivery warehouses closer to more consumers, Amazon had been able to reduce transportation costs to the benefit of its profitability.

Jeff Bezos, founder and CEO of Amazon, said that consumers’ adoption of ebooks was accelerating. Bezos said: “After five years, ebooks is a multibillion dollar category for us and growing fast – up approximately 70 per cent last year. In contrast, our physical book sales experienced the lowest December growth rate [in 17 years], up just 5 per cent.”

Szkutak, however, said Amazon had seen weakness in demand for televisions, digital cameras, MP3 players and for expensive items priced over $1,000. The company was investing heavily in China and in its newest markets in Europe, he added.

Amazon’s shares grew by more than 9 per cent to $284.53 in after-market trading on Tuesday.