According to Nielsen Book, the UK publishing industry is seeing fewer printed books bought as gifts, the number having dwindled by nine million in the span of a year. Overall, the book market dropped by four percent between 2012 and 2013.

The news was revealed in Nielsen’s UK Books & Consumers Annual Review for 2013, which not only showed the decrease in paperbacks and hardbacks (down to 50 percent from 55 percent, and steady at 21 percent, respectively), but also the rise in digital e-book purchases at the expense of print publication sales (up to 25 percent from 20 percent in 2012). In other words, e-books now account for one-fourth of all books bought (up from one-fifth in 2012).

The United States’ publishing industry has seen a similar trend; in 2013, gifts accounted for 22 percent of book sales, down from 24 percent in 2012.

Jo Henry, International Consumer Research Director at Nielsen Book, said in a press release: “In view of the importance of the gift market to the book industry, Nielsen Book Research is proposing a further study to understand what is behind the apparent decrease in the value that consumers are placing on books as gifts and what might be done to counteract this.”

The Books & Consumers survey also noted that adult fiction remains the most popular genre read in digital format at 40 percent of the market; thrillers, crime stories, and fantasies, on the other hand, saw the most growth in 2013.

Erotic fiction—in contrast to the success of Fifty Shades of Grey by EL James in 2012— dropped from 16 percent of the market in 2012 to just 5 percent in 2013. Children’s fantasy and magic stories, including JRR Tolkien’s The Hobbit and Stephanie Meyer’s vampire series Twilight, have dominated the market for the last two years. Adventure stories such as Suzanne Collins’ The Hunger Games saw a decline in sales, falling from 15 to 12 percent of the market.