Amazon recorded a drop in profit for its fourth quarter of 2012, but showed higher revenue, leading investors to push the stock up by more than 8 percent.
Amazon reported earnings dipped to $US97 million ($A93 million) for the quarter ended Dec. 31, from $US177 million reported in the year ago quarter.
Revenue in the quarter was $US21 billion, up from $US17 billion in sales in the same quarter last year.
Operating income in the quarter reached $US405 million, up from $US260 million in the year-ago period.
For the full year 2012, Amazon posted a net loss of $US39 million, down from a profit of $US631 million from the year before. Revenue for the year rose to $US61 billion from $US48 billion the year before.
Amazon does not break out figures for product lines such as Kindle or Amazon Web Services. But CEO and founder Jeff Bezos praised Kindle's performance.
"We're now seeing the transition we've been expecting," Bezos said in a statement. "After five years, e-books is a multibillion dollar category for us and growing fast -- up approximately 70 percent last year."
The earnings report said Kindle Fire HD was the top-selling product across all items available on Amazon worldwide.
"At year-end, Kindle Fire HD, Kindle Fire, Kindle Paperwhite and Kindle held the top four spots on the Amazon worldwide best seller charts since launch," the company said.
Analysts were left guessing about the performance of Amazon Web Services, the company's public cloud hosting service.
However, Amazon said in the release that AWS issued 10 price reductions in 2012, for a total of 24 cuts since the service launched in 2006.
The company also said AWS rolled out 159 new services and features in 2012. This is nearly double the services and features launched in 2011.
Tom Szkutak, Amazon's chief financial officer, said during the earnings call, without offering figures, that Amazon made significant expenditures in infrastructure, including with AWS, for "additional capacity."