Online retailer Amazon this week reported that it has experienced its "best-ever" holiday sales season, thanks to consumer electronics products like the Microsoft Xbox 360, Apple iPod, Cannon PowerShot Digital Elph, and the Garmin global positioning systems. The company also sold a steady stream of DVD movies and video game titles. This was the 12th holiday sales season for Amazon.

Among the impressive statistics racked up by the e-tailer this holiday season: Customers placed more than 4 million orders with Amazon on December 11, its busiest sales day ever. Amazon shipped more than 99 percent of orders in time to meet holiday deadlines worldwide this year. It shipped up to 3.4 million packages out each day. And at one point, Amazon sold 1,000 Xbox 360 consoles in just 29 seconds as part of a promotion that cut the price by two-thirds: Demand for the discounted Xbox 360 was so high that the Amazon.com Web site actually shut down briefly on Thanksgiving Day, the company says.

Other products that sold well include Apple and Sony notebook computers, and wireless accessories such as Bluetooth headsets. The best-selling DVD movie this year at Amazon was "Pirates of the Caribbean: Dead Man's Chest." In the US, the best-selling book was "The Audacity of Hope: Thoughts on Reclaiming the American Dream" by presidential hopeful Barack Obama. In the UK, the best-selling book on Amazon was "Why Don't Penguins' Feet Freeze? And 114 Other Questions," edited by Mick O'Hare.

Overall online holiday spending in the US rose 25 percent year over year, according to ComScore Networks. Online sales for the holiday season--a 45 day period running through December 15, according to the company--hit $19.5 billion in the US.

However, there are some indications that Amazon's successes might not translate to an overall improvement over last year: Visa USA said this week that it is lowering its holiday spending forecast based on weaker-than-expected sales. The company now expects overall spending to rise 6.5 percent this holiday season, down from the previous estimate of 7 percent. Visa's figures include both online sales and traditional brick and mortar retailers.