Originally self-published as ebooks before being picked up by Arrow, the trilogy has broken all kinds of records. More than 20 million copies have been sold worldwide.
Following this phenomenal success, publishers are jumping on the bandwagon and releasing an avalanche of erotica titles.
We have been here before, of course — remember how Dan Brown ushered in dozens of copycat conspiracy thrillers, followed more recently by a never-ending slew of Nordic crime because of the success of Stieg Larsson? Now, thanks to EL James, we're going to find ourselves confronted by more and more "mummy porn" novels.
Harper Collins, Orion and Penguin UK are all rushing out titles in the genre.
Eighty Days Yellow by Vina Jackson — to be followed by Eighty Days Blue and Eighty Days Red — will be published by Orion on August 2.
And Bared to You by Sylvia Day is to be published by Penguin UK today. (In fact, Penguin got so excited about this book they commissioned "a new national bare-all survey into female sexuality" to celebrate its publication. It found that "single women are more likely to have sex in public, fantasise about bondage and use a wider variety of sexual positions" — because we really needed to know that. I won't tell you what it discovered about women in committed relationships!)
If that wasn't enough, other publishers are going a step further by taking classic novels and spicing them up.
Pan Macmillan has charged author Eve Sinclair to given Charlotte Brontë's Jane Eyre an erotic revamp. Jane Eyre Laid Bare will be published as an ebook on August 2 with a paperback to follow in October.
And at the end of this month, Total-E-Bound Publishing is to launch a separate imprint called Clandestine Classics, which will take a handful of classic novels and insert racy scenes into the existing text. Yes, Jane Austen, Charlotte Brontë, Jules Verne and Arthur Conan Doyle must be spinning in their graves.
This shocking development even made the Channel 4 News here in the UK on Tuesday evening. (See video clip above.)
But that's not all! Some publishers are also releasing non-fiction guides — Fifty Ways to Play: A Beginner’s Guide to Unleashing Your Erotic Desires anyone?
And then there's the spoofs, such as Fifty Shames of Earl Grey (to be released on July 31), which is billed as a "shrewd, laugh-out-loud funny and romantic parody". And even Twitter has got in on the act with @FiftyShedsOfGrey — "erotica for the not-too-modern male" — and #Irishshadesofgrey, which offers a humourous Irish alternative.
Of course, erotic literature is not new. Mills & Boon has been publishing bodice rippers for decades — it has now released 12 Shades of Surrender, in ebook format only, in the wake of Fifty Shades — and French-Cuban author Anaïs Nin made a very successful literary career out of it.
But this more recent trend reflects a certain lack of imagination by publishers keen to cash in on a sales boom I assume they don't truly understand. What do you think?