Licensed titles made up 26% of unit sales of juvenile books in the U.S. in 2018, according to just-released research from the NPD Group. The figures include two types of books, says Kristen McLean, books industry analyst for NPD. The first category consists of pure licensed titles, where a book publisher acquires the rights to publish books based on a film, TV show, toy, or other non-book intellectual property. The second consists of titles that originate in publishing but are supported by media vehicles such as movies or TV shows. An example of the latter is Macmillan’s A Wrinkle in Time, which saw a sales boost across all formats due to the 2018 film based on the book.

Licensed titles’ share of children’s unit sales was down slightly from 28% in 2017. “The licensing business is very much about the ups and downs of whatever media is driving it,” McLean says, noting that key properties such as Star Wars and Lego did not have tentpole films supporting them in 2018, affecting sales of complementary books. She adds that changes in the mass market retail landscape, notably the closure of Toys ‘R’ Us stores, may have had an impact as well, since licensed titles rely heavily on that tier of retail.

Licensed books’ share of market value—calculated by multiplying suggested retail price by unit sales—was slightly less, at 22%, than for units. The discrepancy is due to the fact that the highest-volume licensed titles tend to be those in lower-priced formats such as paperbacks, board books, activity books, and coloring books, McLean says.

The bestselling pure licenses in 2018, ranked by unit sales, were Star Wars and Paw Patrol. All told, Disney-owned properties—Star Wars, Disney Princess, Frozen, and “all other”—accounted for four of the top 12 bestselling licenses of the year. Other strong-selling pure licenses in the children’s book industry included Peppa Pig, Dungeons & Dragons, Minecraft, Lego, Sesame Street, Pokémon, and Trolls.

NPD Group estimates that licensing drove 12% of total unit sales of books, for adults and children collectively, in 2018.