Any follow-up to a series which spent 133 consecutive weeks on the New York Times bestseller lists and sold more than 125 million copies is bound to cause a bit of a stir within the market. So it’s little surprise to see the recent release of Grey: Fifty Shades of Grey as Told by Christian generating more than a few headlines around the world scale. The book's release also provides an opportunity to evaluate how the erotic fiction market continues to evolve.

As a genre, erotica has clearly grown. And it continues to see a sustained presence on bookshelves and online marketplaces all over the world. Sales in the category remain particularly strong both in the U.S. and U.K., as well as in European markets such as Germany, Spain, France and Italy.

In fact, here at IPR License, we have just completed an Italian rights deal for a book published by erotica house, Totally Bound. Crave, by Sierra Cartwright, recently sold to Newton Compton. Interestingly, the Italian publisher has subsequently changed the title and is publishing the book as Do Not Leave Me Alone on a Rainy Night, which helps indicate how differently titles are packaged and marketed across territories.

It’s a given that the success of the Fifty Shades trilogy has allowed erotic fiction to become more mainstream in many markets. In India for example, erotica is being read and discussed more openly now. (This, in spite of the fact that India is the birthplace of the ultimate sex manual, Kama Sutra.) Writers such as Sreemoyee Piu Kundu, Ananth Padmanabhan and Sangeeta Bandyopadhyay have really injected new life into this genre.

Of course change happens slowly, though. While some publishers are open to releasing more explicit works, others continue to keep their titles more romance-led. In other words, as this genre has gained in popularity, globally it's also become more segmented and specialized.

Totally Bound, which is based in the U.K., is a good example of how some publishers, in the right countries, are riding the wave of the erotica boom. The house has now morphed into the publishing group Totally Entwined, with a Totally Bound imprint and a separate Pride Publishing imprint, exclusively for LGBT books. On its website, books can also be searched by an array of options--pairing (with sub choices for Male/Female, Male/Male and Female/Female) or menage. The house also has a "heat rating" system, which denotes the graphic nature of the content.

This segregation and specialization has helped when it comes to generating and negotiating international rights and licensing deals. Publishers in each market realize the best fit for them. This ability, to categorize the type of content required, can help match publishers across a range of markets. In recent months we’ve also noted increased interest in illustrated erotic fiction. So could the next big trend be erotic graphic novels? This remains to be seen, but what is clear is that erotic fiction continues to see strong sales levels, and knowing the limitations/appetite of individual territories remains key to maximizing rights and licensing revenues.

Tom Chalmers is the managing director at IPR License.