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In addition, the Kindle was the most popular gift item in the electronics category, and appeared most often on the "wish lists" of Amazon customers.
The only list in which Kindle didn't top other electronics was in the 2008 products reviewed most positively by customers. That honor went to the Samsung 46-inch LCD high-definition TV.
Amazon listed its best-selling items in terms of number of units sold, as opposed to sales revenue. The Nintendo Wii console topped the video-game category, and Microsoft Office Home and Student 2007 was the best-selling software.
The Kindle got a big boost in October when popular talk-show host Oprah Winfrey endorsed the device as her "favorite new gadget" on her afternoon TV show. Although the device is pricey at $359, Winfrey said the Kindle would eventually pay for itself, given that electronic books can be downloaded from Amazon for $10 or less.
The endorsement by the media mogul is the gold ring coveted by many consumer-product companies. Winfrey has proven her star power through the popularity of her book club, which has catapulted many authors to The New York Times best-seller list.
The Kindle's main rival is the Sony Reader. Both devices are roughly the size of a slimmed-down paperback book and are capable of storing thousands of books, magazines, newspapers, or any other electronic document. The devices use the same display technology from E Ink, which displays crisp text that's readable even in sunlight.
A key difference in the devices is how books can be purchased. Sony requires content to be bought on a PC and transferred to the Reader through a wired connection. The Kindle, however, ships with a cellular connection that enables users to buy and download books directly from Amazon. The wireless connection is offered at no additional charge.
Despite the economic downturn that led to a dismal holiday shopping season for many retailers, Amazon claimed the season was its best ever, with 6.3 million items ordered worldwide on the peak day, Dec. 15. Amazon, however, did not disclose revenue figures.