The infamous Fifty Shades of Grey is the fastest-selling adult novel, not only of the last decade, but of all time. British sales are currently at 5.3 million copies, including both physical and ebook numbers. However, the trilogy, which includes Fifty Shades of Grey, Fifty Shades Darker and Fifty Shades Freed, is still a long way of achieving the 450 million record set by JK Rowling’s Harry Potter series, with current numbers off the raunchy sequence at 40 million.
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