When R-rated flick “Fifty Shades of Grey” opened in theaters here in February, the box-office score was a big disappointment with only 364,410 tickets sold.

However, the story was different in the e-book market. The eponymous title, written by E.L. James, nabbed No. 1 in March for several consecutive weeks on major e-book charts, including Yes24, Kyobo Bookstore and Interpark, while the paper copy didn’t even reach the top 10 list. The book’s latest sequel “The Grey” also ranked high on e-book charts since its release in September.

The “Fifty Shades” fad here is a case in point that erotic fiction sells well on e-books, like elsewhere in the world.

These guilty-pleasure books, adorned with scandalous titles and sexy cover art, are catering to e-book readers who are secretly craving the genre, but are too shy to purchase them at physical bookstores.

“I bought the e-book version of ‘Fifty Shades of Grey’ out of curiosity,” said a 29-year-old female office worker, who wanted to be identified only by surname Yoon. “The book was an interesting read, but I would definitely not buy these kinds of books at bookstores. But it’s definitely a quick, fun read.”

In October alone, six books on Yes24’s e-book top 10 chart were R-rated titles. At Ridibooks, another major e-book seller, eight of its top 10 romance titles were X-rated. 

At Kyobo Bookstore, romance genre -- which includes erotica -- was the most popular among all genre fiction in e-books, making up 65.4 percent last year.

“When you read an e-book, there is little worry that the cover is shown to others, like paper books, which makes it an appropriate platform for readers seeking a guilty pleasure,” said an official from Kyobo Bookstore.

By Ahn Sung-mi (sahn@heraldcorp.com)