The impact of "Fifty Shades of Grey" on the porn world is hard to overstate.
The explicit best seller sparked an interest in areas that were largely considered taboo at the time—resulting in a sizable interest in both DVDs that dealt with the subject of bondage and the multiple adult novelty accessories that are part of the culture.
The frenzy over the book has died down over the past year though, and so have sales of sex gadgets, according to industry representatives attending this week's Adult Entertainment Expo in Las Vegas.
"It's not the gasoline that it once was," said Scott Taylor, founder and president of adult film studio New Sensations and adult toy company NS Novelties. "What was most significant for us was the increase in sales of Kegel eggs, which were iconic in the book. At the time, we didn't know how many to order, because it never seemed to be enough. That wave is definitely gone."
Brian Sofer, a strategist for Eldorado, a distributor of sex toys to adult stores, agrees.
"It's definitely contracting," he said. "We certainly enjoyed the publicity it gave our industry, but it was a fluke and those numbers are now correcting."
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However, when the Hollywood adaptation of the novel is released in February 2015, the adult industry hopes for renewed interest.
Adult novelty companies were the biggest beneficiaries of E.L. James' erotic trilogy. Sales of restraints, whips and other items mentioned in "Fifty Shades" skyrocketed by as much as 400 percent at some companies after it became a mainstream phenomenon.
Retailers and most novelty companies were quick to capitalize on the interest, bundling together items and introducing "starter kits" for the curious.
Even long-standing bondage stores saw a surge. Monica Jean, affiliate manager for Stockroom, which has been catering to the S&M community for 25 years, says 2013 saw record sales for the company, thanks in part to its KinkLab line of starter products that launched in 2007.
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While some say that interest has started to cool, sales are still above pre-Christian Grey/Anastasia Steele sexcapades.
"Fifty Shades was an explosion that we didn't see coming," said Marcus West, head of marketing at Evolved Novelties, a manufacturer of adult pleasure products. "Our sales were up something like 70 percent. Today, we're still up year over year, but only about 25 percent."
While sales of handcuffs, whips and other products mentioned in the books may be flagging, many in the adult toy industry say there's still an opportunity to keep overall revenues at higher levels. That's because the novel changed the demographic of who shopped at adult stores.
"There has been an evolution of the retail shop," said West. "For years, it was male dominated, with DVDs making up most of the inventory. Now women are coming in, looking for lingerie or vibrators. It's important that the environment be a warm and welcoming one."
Meanwhile, the adult industry expects to see another boost when the movie hits theaters.
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"We tell retail partners they've got to be prepared for the next 'Fifty Shades' phenomenon," said West. "The hype for the film is going to start building around Halloween and into the holiday season, which is a big period for us. … Now we know what's happening and we can be prepared for it."
—By Chris Morris, special to CNBC.com.