Fifteen years ago, the Philadelphia-based indie Quirk Books, which started as a book packager for publishers such as Chronicle, began publishing its own books, almost exclusively in the gift category. Today, Quirk—still in Philly, away from the industry’s New York hub, and with a full-time staff of 22—has become something of a rock star in the small publishing world, releasing books across categories and finding blockbusters in such books as 2009’s Pride and Prejudice and Zombies and the 2011 YA hit Miss Peregrine’s Home for Peculiar Children.

The original Miss Peregrine’s Home for Peculiar Children sold more than 663,000 units last year, while the movie tie-in edition sold another 188,000 copies, according to NPD BookScan. Both PPZ and Peregrine have led to additional books, and the third Peregrine novel, Library of Souls: The Third Novel of Miss Peregrine’s Peculiar Children, came out earlier this month in paperback.

For Quirk, the method behind its publishing philosophy is simple: live up to the company name. Horrorstör—a book about a haunted Ikea-like store designed in the style of its retail inspiration—is as at home on the publisher’s list as its recent YA title Geekerella. The press is unafraid to take chances, and its staff feels no need to be pinned down to a specific category or trend.

“The lack of a trend is the trend,” said publisher Jason Rekulak, a former Publishers Weekly Star Watch finalist. “We never consciously chase trends. We don’t have meetings where we say, ‘Well, The Life-Changing Magic of Tidying Up is doing really well right now, let’s make something like that.’ And that’s what publishing does. Publishing loves that. ‘If 50 Shades of Grey is working, let’s get our billionaire erotica on. If Harry Potter is working, let’s get our boy wizard on.’ We don’t really do that.”

Quirk keeps to a relatively consistent list of 25 books a year (although the quota isn’t strict) with subjects and styles across the map. So far, the strategy has worked: in 2011, Quirk broke $10 million sales level, and revenue continues to grow.

“We’ve more than tripled our revenue in the past five years,” said Quirk president Brett Cohen. He added that, though the publisher has traditionally performed particularly well in special markets, “the traditional bookstore and online retail channels have been great lately as well. We’ve been publishing a lot more fiction, so we’ve seen a lot more through the traditional book channels. 2016 was our best year yet, and that’s coming off of 2015 being our best year, and 2014.”

Part of Quirk’s success comes from catering to the tastes of its audience, which Cohen calls the “bookish subsect of Comic-Con—the people who like to read high-concept but fun books.” That audience, in combination with the 25-per-year pseudolimit, provides Quirk with just enough constraint to breed creativity. “I think it gives us a great flexibility,” Cohen said. “It allows us to publish into any category as long as it has that Quirky feel.”

Key to Quirk’s appeal is its status as a hands-on house with a distinct list. At Comic-Con, Rekulak and Cohen man the booth themselves in lieu of publicity assistants, and Rekulak stresses that he loves “looking for the little guy,” i.e., authors who might otherwise get overlooked. Part of that comes from simply being out of the industry’s Manhattan-centric loop; Rekulak “rarely” gets pitches from agents or pays six figures for a book—although he said that he is “open” to it. Yet often that willingness to search for grain among the chaff pays off.

One example? Seth Grahame-Smith, whose books, including PPZ and Abraham Lincoln, Vampire Hunter (Grand Central), have led to a lucrative career in Hollywood; the author recently worked on The Lego Batman Movie and is credited as a producer of the upcoming reboot of It.

To celebrate its 15th anniversary, this month the publisher will roll out BookPop, a “plug-and-play” digital kit Cohen compares to those used for events like Star Wars Reads Day, which librarians and booksellers can download and use to host a sort of pop-up Comic-Con–like event. In addition to downloadable activity kits, signs, and a program guide, BookPop will connect stores and libraries with authors for in-store or digital video appearances. The strategy is textbook Quirk—flexible and fan-focused, with an inclination to branch into new terrain.

“The marketplace is in such flux right now—categories are going down and up, and we’re sensitive to that,” Rekulak said. “Picture books are exploding; if we ever have the opportunity to do picture books, we should be open to that. There’s also a growing market to do something with audio. We’re not doing anything different with audio—nothing that nobody else is doing—right now, but I’m thinking about it. You’re just going where the readers are.”

CORRECTION: This article originally misrepresented certain dates, and attributed Rupi Kaur’s illustrated poetry collection Milk and Honey to Quirk; the book was published by Andrews McMeel. We regret the errors.