E.L. James's "Fifty Shades of Grey" trilogy has dominated bestseller lists and bedrooms the world over since its release in May, making the once taboo genre of erotica an international zeitgeist, inspiring everything from a movie adaptation, to lingerie lines and adult toys to cooking books. However, just because we're all talking about erotica, doesn't make it a trend, says author of the bestselling "Crossfire" erotica series Sylvia Day.

"People say there's a trend of best-selling erotic fiction. But what is there? There's 'Fifty Shades' and my 'Crossfire' series. That's not a trend. It's two series," said Day in a recent interview with BuzzFeed.

She continued, "In 2005 and 2006, there were a number of all-digital publishers specializing in erotic fiction, but there was no Kindle or Nook, so you would go to their website and buy and download the file to your computer. This was doing really well, and traditional publishers wanted to start figuring out digital publishing, so they thought this might be the genre to open the door for them. All the major New York publishers, at that point, started publishing erotic fiction. The market was flooded with erotic fiction, but the demand didn't support it. There was too much! So this wave of erotic fiction? It's not new, and it's still a niche genre."

"Some publishers have repackaged their erotic novels from 2005 and 2006, and they may have sold a bit better this time. But we're not seeing enough breakaway hits to indicate a huge genre surge."

One of the only books to challenge James' reign at the top of the bestseller charts in 2012, Day has followed an uncannily similar path to success. Both authors self-published their novels, and formally published books on the same day.

Day wants aspiring writers to know that going the self-published route can work, but it's a job that's far more complex than just writing a novel.

"If someone wants to self-publish, you need to realize you're not just a writer," she said to BuzzFeed.

"You're a publisher and need to be able to compete with big publishers. The idea that you can just slap it together and Photoshop a cover does not demonstrate good business sense. You need to make an investment. So you need to do that, and then consistently do that - most writers don't strike it big on their first book. Some writers write hundreds of books and never strike it big."

Since being published last year, "Fifty Shades" has become notorious for its explicit sexual content and controversial portrayal of a relationship involving BDSM. The novel has sold more than 30 million copies in the U.S., and more than 10 million copies to British readers, making James's book the UK's fastest-selling book of all time.

All three books from James' trilogy have remained in the top five of The New Yorks Times' bestsellers list for over seven months. That is, until Day released the sequel to her first "Crossfire" novel, "Bared to You," three weeks ago. "Reflected in You" was the first novel to dethrone James since it was released in May.

The e-book release of "Reflected in You," also debuted at No. 1 on Amazon's Kindle Book bestseller list, knocking James's books from the top spots.

Day's popularity, and the narrative arch of her "Crossfire" novels have a lot to do with James, and her success, and she's the first to admit that. James' books tell the story of brooding billionaire Christian Grey and the demure flower just begging to bloom Anastasia Steele - Day's "Crossfire" series follows billionaire Gideon Cross and socialite Eva Tramell.

Day says the similarities between their stories though are purely coincidental, and that those traits shouldn't surprise anyone who's familiar with erotica because "the tortured millionaire hero" is a cliché of the genre. Noting she has formally published other novels prior to the success of her "Crossfire" series, the author says the commonalities between her and James end there.

"I've been traditionally published for my whole career, starting in 2004. I'm contracted with several different publishers - I write historicals, paranormals, fantasy, everything. It's all spread out among various publishers. I had the idea for this character while I was on deadline for another contracted book."

But, while her first novel, "Bared to You," unashamedly struck many similar notes to "Fifty Shades," fans are reporting that "Reflected in You" is better and an encouraging step in a new direction. The book currently has a rating of 4.6 out of 5 on Amazon.