Kindle e-books selling better than paperback books

Amazon says that, for the first time, it has sold more Kindle e-books than paperback books. Since the start of the year, Amazon has sold 115 Kindle books for every 100 paperbacks. Kindle book sales continue to outpace hardcover sales, as well; during the same time period, three times as many Kindle books were sold as were hardcover books (including sales listings for books that have no Kindle edition).