You know a book is truly successful when a drop in sales in newsworthy
Sales of E L James' Fifty Shades trilogy of erotic novels have fallen for the first time in two months.
After increasing for eight consecutive weeks, last week sales slipped by 16% to 1.21m (£5.4m), according to industry publication The Bookseller.
However the British novelist still topped bestseller lists by a huge margin, with the first book Fifty Shades of Grey shifting 534,088 copies.
The trilogy's closest rival Flesh and Bones by Kathy Reichs sold just 23,871.
"At some point all books are going to reach their peak," explained The Bookseller's Charts Editor, Philip Stone.
"I think Fifty Shades reached its peak the week before last when it sold 1.4 million. The media were talking about it all the time, it was on The One Show and had had a lot of coverage in the press the weekend before."