Amazon's Kindle E-Books Outselling Paperbacks and 'Harry Potter'

Microsoft revenue also boosted by a digital device, with Kinect gaming sensor overwhelming company's sales expectations by three million.

In 60 days Microsoft sold 8 million of its Kinect sensor devices, a $150 gadget that makes the Xbox behave like a souped-up Nintendo Wii, blowing past the company's estimate of 5 million.

MIcrosoft made the announcement Thursday while disclosing financial results from its fiscal second quarter, where net income fell fractionally to $6.63 billion on revenue that rose 5% to $19.95 billion.

Thanks to Kinect, Microsoft experienced 55% growth in revenue at its Entertainment & Devices Division.

Microsoft stock was little changed on the day both before and after the regular trading session.

Also on Thursday, reported fourth-quarter results that did not impress investors and sent the stock down 9% in afterhours trading, after having gained 5% to $184.45 during the regular session.

Net income rose 8% to $416 million on sales that rose 36% to $12.95 billion. Light revenue relative to what analysts had predicted and a forecast of weaker-than-expected margins are probably what spooked Wall Street.

Amazon said that it is now selling about 115 Kindle books for every 100 paperbacks it sells and that the Kindle device has surpassed the book Harry Potter and the Deathly Hallows as the bestselling product in Amazon history.

Nevertheless, media sales at lagged other categories. Worldwide media sales grew 12% to $5.23 billion compared to 60% growth in worldwide electronics and general merchandise to $7.39 billion.