It’s the day before Valentine’s Day at Mischievous Pleasures, an adult novelty store in Salt Lake City, Utah, and sales associate Trent Van de Kamp doesn’t have time to talk. He’s staring down 20 customers and offers to chat next week, but confirms what a number of salespeople at adult stores across the country -- even in the Bible Belt and so-called flyover states -- told International Business Times: E.L. James’ erotica phenomenon, “Fifty Shades of Grey,” has increased sales by “at least 30 percent.”

And the U.S. release Friday of the “Fifty Shades of Grey” film adaptation, starring Jamie Dornan as dominant Christian Grey and Dakota Johnson as newbie submissive Anastasia Steele, is no doubt going to keep sales of blindfolds, handcuffs and crops going strong.

The type of woman walking into Mischievous Pleasures to purchase blindfolds and kegel exercise balls, or Ben Wa balls -- both of which are featured in the book -- is increasingly “an ordinary housewife,” Van de Kamp said.

“Before, it was the husband coming in and saying, ‘I’d like to surprise my wife,’” said Amanda Thornton of Priscilla’s Adult Novelties in Lincoln, Nebraska. “Now, it’s the wife coming in and saying, ‘I’d like to surprise my husband.’”

When asked what impact “Fifty Shades of Grey” has had on Priscilla’s sales, Thornton replied, “It has doubled -- if not tripled -- the sales of light BDSM-related products: crops, whips, handcuffs and blindfolds.” And once customers are in the shop, she said, they stay and buy more.

“We’re conservative in Lincoln, Nebraska,” Thornton said. But these days, one of the most familiar questions she gets is,“What are those balls in ‘Fifty Shades Of Grey?’” Ben Wa balls are what they’re referring to, she explained, and they’re basically “weighted balls that you put in your vagina and use to do Kegel exercises,” which are designed to help women improve their ability to have orgasms.

Customers are practically using “Fifty Shades of Grey” as a blueprint for their new erotic adventures. “‘This is what I saw in the book,’” Thornton said customers will say to her. “‘That’s what I need.’”

20150213_140411 Sex sells at Priscilla's Adult Novelties in Lincoln, Nebraska. And "50 Shades of Grey" has helped increase sales by as much as 30 percent. Photo: Priscilla's Adult Novelties

When asked to explain what she thinks the book’s appeal is to these women, she replied, “They’re looking for the same experience of the book: The seductive, romantic mysterious love that Christian Grey offers.” She said they’re also curious about bondage, dominance, sadism and masochism, which has associations with extreme pain. The book “sparks their curiosity,” she said, because it suggests BDSM can be about “more of a sensual pain.”

Although the book has given some of Priscilla’s customers permission to partake in kink because “everyone in the world is doing it,” Thornton said they still ask for their products to be double-bagged.

At Romantic Adventures, an adult-entertainment store in Jackson, Mississippi, store manager Ashley Meetze said she’s seen a steady climb in the sales of sex toys and BDSM-related products since “Fifty Shades of Grey” came out. And she said that between 30 percent and 40 percent of her customers are coming in because of the book.

It’s gotten to the point, she said, that someone will come in and start off by saying, “I just read ‘Fifty Shades of Grey’ ...” and she’ll respond: “I already know what you’re going to say. Now, how can I help you?”

“As for the Ben Wa balls,” she said, “at one point we couldn’t even produce them fast enough.”

In addition to encouraging couples to “play” and helping bring kinks out of the closet for many, said Meetze, “Fifty Shades of Grey” has burnished Mississippi’s so-called bad reputation. Mississippi led the way in U.S. presales of the “Fifty Shades of Grey” film, and Romantic Adventures is giving away 1,000 tickets to the movie.

“In the Bible Belt, sex is hidden, and it has been for so long,” Meetze said. “You only ever hear bad stuff about Mississippi. But publicity about the ticket sales is painting Mississippi in a good light.”