Dec 27, 2010 15:41 GMT  ·  By

This holiday season has been especially lucrative for online retailers if Amazon is anything to go by. The company just announced record sales for Cyber Monday, on average, 158 items sold every second, and that its Kindle e-reader is now the best selling product on the site of all time, surpassing the final Harry Potter book.

“We're grateful to the millions of customers who have made the all-new Kindle the bestselling product in the history of Amazon -- surpassing Harry Potter 7,” Jeff Bezos, founder and CEO of Amazon, said

"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," he added.

This is an interesting point, but without any data it's hard to put it in perspective. The Kindle clearly can't compete with tablets, especially the very popular iPad, and positioning it as a complementary device is a much better strategy.

At $139 for the WiFi only Kindle 3, it's well below the iPad's price point, but, even as Amazon boasts record sales, some overlap between the two devices and lost potential sales for the Kindle are inevitable.

Still, the holiday season proved very big for Amazon and the Kindle in particular. November 29, Cyber Monday as it is known, was Amazon's biggest day in history with 13.7 million products sold worldwide in the 24 hour period.

The Kindle was Amazon's biggest selling product overall. However, Amazon still hasn't released any actual sale numbers. No surprise, Christmas Day saw the most product activations for the Kindle as well as the most e-book purchases than any other day in history.

"The Girl with the Dragon Tattoo" was the most purchased and the most gifted e-book on Christmas Day, Amazon also revealed. When it comes to devices, the Kindle WiFi was the most popular followed by the Kindle 3G. Interestingly, the iPod Touch 8 GB came in third, showing that there is a lot of interest in the often overlooked device.