Sales of digital e-books have outstripped real books for the first time, according to Amazon.

The firm said that it has sold 143 e-books for its Kindle e-reader for every 100 hardcover books over the past three months. That rate has accelerated with Amazon selling 180 e-books for every 100 hardcovers in the past month.

Amazon’s Kindle bookstore now offers more than 630,000 books. Over 510,000 of these books are $9.99 or less

Amazon.com announced that sales of its Kindle device had also accelerated over the past three months, a change that the firm described as a ‘tipping point’.

Jeff Bezos, Amazon’s CEO, said: `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.

Users of Apple`s new iPad downloaded 1.5million digital books in the tablet`s first month on release.

Users will also have access to over 12million books, both in print and out-of-print, already scanned by Google. This vast library is greater than the selection of material available through Amazon or Apple.

BDST: 1535 HRS, 20 July 2010