Yesterday, Amazon sent out a press release announcing that eBook sales have now outpaced hardcover sales and touting the increased sales of lower priced Kindle units. Jeff Bezos, Amazon CEO, stated, “Amazon.com customers now purchase more Kindle books than hardcover books – astonishing when you consider that we’ve been selling hardcover books for 15 years, and Kindle books for 33 months.” In the past three months Amazon has sold 143 Kindle books for every 100 hardcover books it has sold in the U.S. In the past month, Amazon has increased that ratio by selling 180 Kindle books for every 100 hardcover books it’s sold. The number of eBooks sales in the first half of 2010 is more than triple the number sold in the first half of 2009. Amazon also applauds a group of five authors that have sold more than 500,000 Kindle books. Charlaine Harris, Stieg Larsson, Stephenie Meyer, James Patterson, and Nora Roberts have all passed the half million mark.

Lowering the price of the Kindle earlier this year has helped Amazon increase Kindle sales during the second quarter. “We’ve reached a tipping point with the new price of Kindle – the growth rate of Kindle device unit sales has tripled since we lowered the price from $259 to $189,” said Bezos.

Yet, even with all the good sales news, Amazon still faces some stiff competition from other eReader devices. “The Kindle, while great for reading, still offers only a fraction of what the iPad can do… And I suspect another Kindle price cut down to $99 may be coming sometime in the next year. If Apple stays at $499 for the iPad, that should be enough to differentiate itself for a while. Amazon is also smart to offer its Kindle software on devices like the iPad, iPhone, and Android phones. This ensures that Amazon’s future in the book business will remain intact whether or not they’re the ones in charge of the hardware,” writes MG Siegler on TechCrunch.