'Fifty Shades of Grey' reaches 100 million sales landmark
The trilogy of EL James's erotic romance novel Fifty Shades Of Grey has sold 100 million copies worldwide.
The series - dubbed "mummy porn" - is fast becoming one of the most widely read book series.
It has been proved so successful that the film version has been created and is expected to hit the screens in time for Valentine's Day 2015.
As well as selling 27 million copies in the UK and Commonwealth counties, Arrow Books has also sold one million copies or more in Germany, France, Spain, Brazil, and The Netherlands.
Vintage Books sold more than 45 million copies of the trilogy in the US in both print and eBook.
Two copies were sold every two seconds during peak sales and it is the fastest selling book series in the history of Random House.
Stephenie Meyer's famous vampire romance Twilight has sold 120 million copies worldwide and C.S Lewis' children's classic The Chronicles Of Narnia, which was penned in 1959.
Anne Messitte, publisher of Vintage/Anchor Books in the US said: "We see new readers coming to the books every day and the sales, two years after our initial publication, remain strong and steady."
The trilogy has been translated into 51 different languages, including Russian, Hebrew, Thai, Serbian, Mongolian, Icelandic, Latvian, Korean, Lithuanian, and Slovak.
The movie - being directed by artist and film-maker Sam Taylor-Johnson - was due to be unveiled next August, but as put back until 2015 having been dogged by difficulties with casting.
The production delay was thought to have been partly as a result of the abrupt exit of star Charlie Hunnam, who left citing his busy schedule and family commitments.
He has now been replaced by Jamie Dornan, seen by TV viewers in BBC thriller The Fall.