If you follow the publishing industry at all, the chances are you’ve heard of Fifty Shades of Grey by E.L. James. For the uninitiated, this is the first title in an erotic trilogy that first garnered attention as a popular e-book climbing the rankings at Amazon.com. It later went on to have a small printing through an Australian publisher, and just this week sold at auction for a reputed seven-figure sum (for the trilogy) to a major New York publishing house. The original e-book version was pulled from all vendors and a new, more expensive copy loaded in its place. At this point, hard copy orders still result in the print copy from the Australian printing, though the official listing has the name of the New York publisher.

So what’s the big deal? This title has already sold approximately a quarter of a million copies, and will be receiving a reported 750,000 copy print run under the new publisher. Someone, somewhere, feels there is a market for a million copies of this book. Maybe they’re right, maybe they’re wrong, but the real question is why do they feel this is worth the gamble?

The Shades of Grey books began their lives as Twilight fan fiction, reimagining Bella as an innocent young woman just graduating college who enters into a BDSM relationship with a wealthy Seattle businessman–Edward. The combination of the subject matter, which was handled in an almost tutorial-like fashion as Edward “educated” Bella about the lifestyle, and the Twilight link, made the stories incredibly popular with their audience, which was Twilight fans interested in a more adult view of the relationship from the original Stephenie Meyers books. Subtract vampires, add sex. E. L. James gained a measure of fame within fandom and beyond, and eventually decided to pull the fan fiction version of her stories from the internet, change the details to make them completely original fiction, and publish them in electronic form. Many of her fans supported her, and sales increased thanks to word-of-mouth.

It remains to be seen how many “mainstream readers” — meaning those not plugged into the internet or fandom — will be interested in these books in their latest incarnation. While some areas of the media seem to consider it a revelation that there are women out there interested in reading about sex — and not just your standard variety, missionary position sex, either — the reality is that the erotica market has experienced several major upticks in recent years, spawned in large part by the online vendors and the availability of electronic formatting. This is the equivalent of the brown paper wrapper; naughty, sexy reading material that you can download at will and delete or store in the cloud when you’re done. Will readers embrace these books to the point of purchasing them in paperback? Do three quarters of a million readers want these books on their shelves? I don’t know.

These books are not art. They are not even particularly original or well written. What they are, is an exploration of a world that hasn’t received much public attention recently. It’s impossible to point to the market and say “this is what you need to do to sell a lot of books.” People’s interests are not that cut and dry. You can, however, analyze successful titles to see what has made them different. In this case, the author is giving the reader a tour of the BDSM world, something many of them have never read about or heard much about in their daily lives. I suspect there is also a level of curiosity about the titles for those readers who are familiar with the BDSM lifestyle — wanting to know if the author has her details right. Layer that on top of a relationship that is fashioned after one that’s already proven highly successful, and you begin to get a glimmer of why these books are doing so well.

It’s easy to say sex sells, and that the titillating aspects of the books are the draw, but the original Twilight novels included very little sex and have been enormously popular. So clearly sex alone is not the key.

What makes a bestselling book? There really is no one thing, no formula. If you look back at the vampire craze of the late seventies and early eighties, you find the novels of Anne Rice. Rice’s Lestat books were fresh and different in that they gave the reader the vampire’s point of view. Rice asked what it would be like to live so long, to be forced to keep up with history and technological advances, to see everything you knew and loved as a child or young adult gradually change and vanish — the experiences of becoming old but in the extreme. What is it like to have no one to live your life with? What is it like to have that level of power over humans? And what would it be like to be turned as a child, to age and mature over the years while your body remained undeveloped? Her approach was intriguing, her characters fascinating and multifaceted compared to the more traditional vampire stereotypes. Set against the lush backdrop of New Orleans, with Rice’s stylistic, almost baroque writing — very in keeping with the over-the-top eighties — the books became a sensation.

The Harry Potter books are another example of a fresh take on old ideas. J.K. Rowling’s series is far too popular for anyone to simply dismiss her as lucky, or the books as children’s literature that happened to appeal to a lot of readers. Statistically speaking, a huge proportion of the population has read at least one Harry Potter book or at least seen one of the films. They are well crafted, thoughtfully plotted, and packed full of details that make readers wish they could visit Rowling’s world — enough that one theme park has been built to answer to that desire, with another one in the works.

Yes, Rowling started writing about wizards at a time when fantasy was just experiencing a resurgence in literature — and she likely contributed to that rise. She also set her stories in a boarding school, a fascinating new world for readers in the US where most children attend school locally, thereby layering her intriguing worlds instead of supplying just one. But the reality is that the stories engage readers through multiple themes and age-old traditions of literature. They are packed with examples of good versus evil, practicing what you preach, being tolerant, how even the best people can be hypocritical, following your conscience, standing by your friends, and much more. At a deeper level, there are religious themes of rebirth and resurrection that tap into cultural beliefs. And of course, all of this rests under the veneer of a series of mysteries the characters must solve, not only on a smaller level — one for each book — but on a grand scale across the series. These are books that may be read for pure enjoyment, but they also stand up to rereading and to digging deeper for a greater meaning — which cannot be said of many of the Harry-inspired titles that have been published in years since.

Popular author Tom Clancy has detailed knowledge about how our military and government work to keep the country safe, and an interest in the broader political area, that allowed him to craft very in-depth action adventure books that put the reader in the thick of the action. But his sales were definitely boosted when a certain President of the United States mentioned he was reading a Clancy title. The books were well written, and worth the discovery once a reader picked them up, but they found their market through the best sort of word-of-mouth. More recently, Joseph O’Neill’s Netherland received a presidential mention as well. And many books have achieved high sales thanks to their Oprah Winfrey book club listings.

The market is a strange and fickle place. It is virtually impossible to plan for success — to sit down and decide to write a particular type of book, including specific details, and know that it will fly off the shelves. Tastes change rapidly, and what is popular when you pick up your pen or sit down at the keyboard might very well be last week’s news by the time you finish your first draft. As for publicity, well, unless you know a book-minded politician who likes to name drop, or are on Oprah’s Christmas card list, the chances are good that you can only dream of your book receiving that sort of endorsement. There will always be fads, there will always be fascination based on some quirk of the times we live in, and there will always be lucky coincidences that can help a writer soar to recognition. But these are just the fates at work.

Writers can only control so much of their career and their process. You have to write, and rewrite. You have to read good books, and the occasional bad book, so you know what makes them what they are. Read the bestsellers to see what is working but form your own opinions. Just because it sells, does not mean you’ll like it — or that it is the type of material you wish to write. Write from the heart and keep at it, and know that while certain levels of success will always be a matter of luck, your talent and efforts will eventually pay off.