The debut book by racy publishing phenomenon EL James, Fifty Shades Of Grey, has become the first to sell more than one million copies on Kindle.
Online retailer Amazon.co.uk says James - whose real name is Erika Leonard - has already become its best-selling author of the year and the book is the biggest Kindle ebook yet.
Sales of the book, dubbed "mummy porn" for its steamy content, have continued soaring with the paperback version achieving the UK's highest weekly sale for a paperback.
Amazon said the Kindle edition of Fifty Shades was outselling the print book at a rate of more than two to one.
Her trilogy of saucy Grey books was published in March. The film rights have already been snapped up.