Online retailer Amazon on Monday said its latest Kindle had become the company's best-selling product ever.

Without giving details of the number of units sold, the company said sales of its third generation e-reader had beat sales of "Harry Potter and the Deathly Hallows."

Jeff Bezos, Amazon.com founder and CEO, said the product's 139-dollar price tag meant owners of tablet computers, such as the iPad, were also buying Kindles.

"We're seeing that many of the people who are buying Kindles also own an LCD tablet. Customers report using their LCD tablets for games, movies, and web browsing and their Kindles for reading sessions," Bezos said.

Amazon also announced that it sold around 158 items a second on the peak holiday sales day, November 29 -- dubbed "Cyber Monday."