What surprising revelation did Amazon announce on Thursday?

Answer: That they now sell more e-books than print books. In a May 19 press release Amazon said "Since April 1, for every 100 print books Amazon.com has sold, it has sold 105 Kindle books. This includes sales of hardcover and paperback books by Amazon where there is no Kindle edition. Free Kindle books are excluded and if included would make the number even higher."