The Fifty Shades of Grey trilogy has now sold over 100 million copies worldwide making it one of the most widely read book series in history.
Around 27 million copies have been sold in the UK and Commonwealth countries, while over one million copies have been bought in France, Germany, Spain, Brazil and the Netherlands.
Publishers Vintage Books said they had sold more than 45 million copies of the trilogy in the US in both print and eBook.
The popularity of the El James's erotic novels, which has been translated into 51 different languages, have sparked the creation of a film which is expected to hit screens in time for Valentine's Day 2015 after difficulties with casting.
Two copies were sold every two seconds during peak sales and it is the fastest selling book series in the history of Random House publishing company.
The sales put the novel on similar figures to Ian Fleming's James Bond series, Stephenie Meyer's famous vampire romance Twilight and C.S Lewis' The Chronicles Of Narnia - although it still has some way to go to beat JK Rowling's Harry Potter which has sold 450 million copies.