Online retail giant Amazon claims it has sold more than a million Kindles - including ebook readers and its Fire tablet - each week for the past three weeks.
Amazon has never released complete sales figures for the ereader devices, but has previously said ebooks are outselling new paperbacks and hardcover editions.
The sales jump is apparently boosted by the Kindle Fire, with Amazon claiming the tablet is its best-selling product.
“Kindle Fire is the most successful product we’ve ever launched – it’s the bestselling product across all of Amazon for 11 straight weeks, we’ve already sold millions of units, and we’re building millions more to meet the high demand," said Dave Limp, vice president of Amazon Kindle. "In fact, demand is accelerating. Kindle Fire sales increased week over week for each of the past three weeks."
The Kindle Fire has yet to be released in Australia, but is expected to arrive some time next year. Its software has already been updated twice, with the most recent upgrade including a fix for a privacy flaw.
The Kindle Fire has been tipped by industry analysts as the first real rival to the iPad. Apple is much more open about sales figures, saying it shipped 11m tablets last quarter.