5.3 million of us have bought either a physical copy or a more discreet e-book version of the novel that has been writing its own headlines (or producing its own parodies) for months.
It has now sold more copies than The Highway Code - an astonishing feat for a novel that is primarily only aimed at 50% of the population.
50 shades
Author EL James - who's story began as a piece of Twilight fan fiction - said: "My main ambition when I signed the deal with Random House was to see my books in the shops.
"I simply had no idea they would be so successful and this is totally unexpected."

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