Amazon.com's Kindle DX reader, with a larger screen, is made to read publications such as newspapers or textbooks. Amazon.com's Kindle DX reader, with a larger screen, is made to read publications such as newspapers or textbooks. (Amazon)

Amazon is busy hailing the success of its e-reader, Kindle, but the online retailing giant is still refusing to release specific sales numbers.

Amazon reported Q4 earnings on Thursday that beat analysts' expectations — $384 million US, or 85 cents a share. That represented a 71 per cent jump from the same quarter a year earlier.

Revenue in the three months ending Dec. 31 soared 42 per cent to $9.52 billion as consumers spent more during the holidays.

Analysts were eager to learn how the Kindle has been selling, but the company was short on hard details.

"Millions of people now own Kindles," was all Amazon CEO Jeff Bezos would reveal in a statement. As vague as that statement is, it's the first numerical acknowledgment from Amazon of the e-reader's success.

"Kindle owners read, a lot," Bezos continued. "When we have both editions, we sell six Kindle books for every 10 physical books."

The Kindle was released in Canada last November and the company said it was one of the most popular items purchased through its online store during the month.

The basic Kindle sells for $259 US in Canada, plus import fees that add about $31.

iPad competition looms

By some estimates, Amazon sold as many as two million Kindles last year, giving it an e-book market share in the U.S. of almost 60 per cent.

Amazon is clearly enjoying Kindle's current dominance in the growing e-book sphere. But this week's announcement by Apple of its iPad tablet device raised immediate debate over whether it would be a "Kindle killer."

In the confence call following Amazon's earnings release, analysts tried repeatedly to wrestle more specific Kindle sales figures or outlook from company management, but without success.

Amazon CFO Tom Szkutak said the company was excited about its growth prospects and Kindle's success versus iPad going forward.

"We believe that readers deserve to have a dedicated device with great selection at great prices," he said.

On Wednesday, Apple launched iBooks in conjunction with the iPad, a service that lets users buy and download books straight to the device. Penguin, HarperCollins, Simon & Schuster, MacMillan and the Hachette Book Group were announced as partners.

Analysts are forecasting that Apple will ship as many as five million iPads in 2010.

Amazon stock gained in early Friday trading but ended the day with a loss of 26 cents at $125.41.