We won’t have the full picture until sometime in 2015, but as it stands right now, book publishing had a profitable year in 2014. In the face of constant fighting between the Big 5 publishers and Amazon, book sales are up across all categories by 4.9 percent, according to the Association of American Publishers (AAP).

Even trade sales, as it turns out, are up 2.8 percent this year. And — in a turn of events that should surprise no one — those trade sales were buoyed by a substantial increase in sales of Young Adult and Children’s books, up 22.4 percent over 2013. When you also consider that religious-press books are up by a meager 2.1 percent, and that, horrifyingly, Adult Fiction/Non-Fiction is down by 3.3 percent over last year, it becomes obvious that YA/Children’s books are keeping the industry out of the red.

Ebook sales — which were thought to be declining — are up by 5.6 percent in trade. Hardback sales are down a percentage point, while paperbacks are still strong at an increase of 4.9 percent.

But here’s where things get curious: ebook sales are up by nearly 53 percent in the YA/Children’s book category. This implies that YA/Children’s book are substantially driving total ebook sales. And yet! We have new information that teens, in fact, prefer print books to ebooks. “The reading habits of those aged 13-17,” Nielsen writes, “are a mix of old and new”:

Despite teens’ tech-savvy reputation, this group continues to lag behind adults when it comes to reading e-books, even with the young adult genre’s digital growth relative to the total e-book market. While 20% of teens purchasing e-books, 25% of 30-44 year olds and 23% of 18-29 year olds buy digital copies. While younger readers are open to e-books as a format, teens continue to express a preference for print that may seem to be at odds with their perceived digital know-how.

The takeaway from this might not shock you, but it is substantial: It now seems clear that the healthiest market for trade books in 2014 includes adults who buy ebook versions of YA/Children’s books. In a way, these numbers retroactively justify a year of debates over the distinction between children, teenagers, and adults. The numbers also validate an argument I made earlier about the genre wars and the subsidization of literature by YA and genre books.

Although it remains to be seen how the dominance of serial fiction has affected the publishing industry in 2014, we do know that Amazon’s list of 2014 best-sellers featured a majority of fiction serials. It’s no secret that among the subsections of trade books listed by the AAP, YA and Children’s books are the more likely to feature serial storylines. And if the inclinations of teenagers are any indication, serial fiction will continue to excel in 2015. More than any other influence, teenagers said, enjoying a previous book from an author is what drives their decision to read.

One may argue that if publishing was profitable in 2014, it was pointless for the Big 5 and Amazon to engage in a yearlong battle over pricing. But if we look at the numbers here, it’s obvious why these giants locked arms: trade ebook sales are still relatively strong, so of course there is a battle to set prices. And even if a deal was reached between mortal enemies Hachette and Amazon, it looks like Bezos is still calling for lower book prices. In an interview with Business Insider, a magazine where he is the lead investor, Bezos made his case:

Books, in my view, are too expensive. Thirty dollars for a book is too expensive. If I’m only competing against other $30 books, then you don’t get there. If you realize that you’re really competing against Candy Crush and everything else, then you start to say, “Gosh, maybe we should really work on reducing friction on long-form reading.” That’s what Kindle has been about from the very beginning.

Going forward, though, into 2015, I suspect the industry conversation will move from pricing to the problem of marketing. Younger readers prefer bookstore and libraries for finding books, and as much as I like to hear this, I suspect that for Bezos and big publishing, this will not be enough. We can already see moving and shaking on the part of big publishers in this respect. Simon & Schuster increased their coop funding to Amazon — monies that guarantee top placement on Amazon’s site. And Hachette, fresh from its battle against the retail giant, recently announced that it will sell books directly on Twitter. And who cites Twitter as their most used social media platform? Teens. Here’s looking at you, Instagram.