It would be interesting to see how Apple’s iBook store sales levels compare
Amazon began selling hardcover and paperback books in July 1995. Twelve years later in November 2007, Amazon introduced the revolutionary Kindle and began selling Kindle books. By July 2010, Kindle book sales had surpassed hardcover book sales, and six months later, Kindle books overtook paperback books to become the most popular format on Amazon.com. Today, less than four years after introducing Kindle books, Amazon.com customers are now purchasing more Kindle books than all print books - hardcover and paperback - combined.
"Customers are now choosing Kindle books more often than print books. We had high hopes that this would happen eventually, but we never imagined it would happen this quickly - we've been selling print books for 15 years and Kindle books for less than four years," said Jeff Bezos, Founder and CEO, Amazon.com.