Since Harry Potter first hit these shores in 1998, there’s been confusion over where best to shelve it: put it where most kids look for it, in middle grade (ages 8–12), or where the later, darker novels belong, in young adult (ages 12–up)? But J.K. Rowling’s books aren’t the only ones that fall into a gray area, especially as more kids aspire to “read up” because of popular films like Divergent and The Hunger Games. At the same time, adults have begun reading down, not just YA but also reaching for middle-grade books like Wonder and Out of My Mind, because they don’t want to miss out, either.

The convergence has gotten so great that when PW recently compiled its list of the top-selling titles of the first half of 2014 using Nielsen BookScan figures, the top six were YA novels: the three books in the Divergent trilogy, along with three editions of The Fault in Our Stars. Hard Luck, which is part of the middle-grade Diary of a Wimpy Kid series, clocked in at #8. With so many different age groups attracted to both middle grade and YA—teens, tweens, and adults—does it still make sense for middle grade and YA to be shelved in separate sections? Is it easier for readers to find books organized by categories based on age distinctions that seem increasingly meaningless? Would it be better to put all preteen and YA books together? Or are the current categories still the best way to help readers find the right book? We spoke to several retailers about their strategies.

For Meghan Dietsche Goel, children’s and YA book buyer at BookPeople in Austin, Tex., and program director of the Austin Teen Book Festival, the “key is simply to talk up the books that you think are right for the kid in front of you and not to talk about what age they are written for. We carry a broad variety of books at a wide range of levels, even within YA or middle grade.” She points to YA books on the “gentler end of the spectrum,” like Maureen Johnson’s 13 Little Blue Envelopes, Roland Smith’s Peak, and Michelle Cooper’s A Brief History of Montmaray, as well as middle-grade titles like Cathrynne M. Valente’s The Girl Who Circumnavigated Fairyland in a Ship of Her Own Making and Jacqueline Kelly’s The Evolution of Calpurnia Tate, which appeal to teens who may not be ready for sophisticated content.

The biggest difference at BookPeople between middle grade and YA is the way they are marketed. Middle-grade bestsellers are driven by the store’s Booktalk program: BookPeople’s outreach coordinator visits more than 80 schools a season to talk about new books. “Middle-grade readers really respond to an opportunity to connect with an adult who loves books as much as they do,” says Goel. On the other hand, YA sales are built on word of mouth, largely spread by the store’s Teen Press Corps. This group of teenagers helps the store select a YA Buzz Book each month, discusses book news on, and writes reviews that are featured on shelf-talkers in the store’s YA section.

At six-year-old Green Toad Bookstore in Oneonta, N.Y., where kids’ books comprise about one-third of the store’s space, middle-grade and YA books are shelved next to each other, and new releases for each age group are featured side-by-side on a display table. Although owner Michele Barry would like to see middle-grade readers maintain their innocence for as long as possible, she won’t deny tweens a book they want to read. She will, however, warn an accompanying adult that it may feature sexual content, drug use, or language they don’t want their child to read. “Ultimately it is up to them,” she says.

The problem arises when it’s a parent or grandparent who is choosing what the child should read. “Some parents and kids have very different ideas about what they want to read more of,” says Nicole Yasinsky, children’s manager of the Booksellers at Laurelwood in Memphis. “I have had to be the decision-maker, and sometimes the ‘bad guy,’ for families with very gifted readers who may not be ready for the content that YA offers.” She also has to steer readers at the other end of the spectrum toward high-interest, low-level books.

One way the store bridges the gap is by shelving middle-grade, or “Intermediate,” fiction along with YA in a separate room that has two entrances, including a doorway that connects it to the rest of the kids’ section. And although books are marked YA or middle grade based on catalogue information, when they come in Yasinsky will decide if they’re in the right place. Occasionally she will switch them.

Like BookPeople, the Booksellers at Laurelwood and its sister store, the Booksellers on Fountain Square in Cincinnati, work with local schools to spread the word about upcoming author visits. “We often try to reach parents via social media and our newsletter, and parents and students together by contacting schools,” notes Erin Mays Caudill, who buys kids’ books for both stores. In the case of YA writers, she reaches out directly to teens via the store’s social media accounts.

“I think there will always be and will always need to be separate sections for middle-grade and YA fiction,” says Caitlin L. Baker, children’s buyer at University Bookstore in Seattle. The store has separate sections for early readers (8–12) and middle-grade fiction (10–14) as well as teen fiction (14 and up). It also has enough space to double-shelve a few series like Phyllis Reynolds Naylor’s Alice books. “The only area we have middle grade and YA mixed is our graphic novel section,” she adds. “I’m going to look into dividing [it] soon.”

Children’s Book World in Haverford, Pa., is one of the few stores that forgoes signage altogether, even though its books are broken out by sections. “We have found that children’s reading levels are incredibly varied and their life experiences cover even a wider range,” says manager Heather Hebert. “The last thing we want is to make a child feel they need to read something above or below their level just because a sign dictates that is where they belong. For us, not having signs allows our customers to go back and forth from different sections in order to find the right book.”

The store uses a similar approach when it comes to shelving. Its YA section, which is primarily for 14 and up, also has a lot of “clean teen” fiction that appeals to both teens and tweens. “We have found that keeping these books near other more obvious YA books makes them acceptable for the 16-year-olds to read. And [it] also lets us pick an appropriate book for a tween who wants to read something that feels older but might not be ready for intense high school content,” says Hebert.

Rather than find categories or signage inhibiting, Amy Oelkers, events coordinator at the Red Balloon Bookshop in St. Paul, Minn., says she would like to add more. The store already has one middle-grade section and two for YA—realistic/contemporary and sci-fi/fantasy. “We live in a golden age of books for young people,” says Oelkers. “At Red Balloon, we have played around with the idea of adding a category for ages 10 to 15. I don’t know what we’d call it, but the need is there. A generation ago, books specifically for young people, especially teens, were few. Now the market has exploded, allowing for and requiring more categories for discovery.”

To facilitate booksellers’ shelving and handselling efforts, publishers try to signal whether the book is middle grade or YA by its cover. “Instead of trying to telegraph what category that is,” says Jen Besser, v-p and publisher of children’s books at G.P. Putnam’s Sons, “your goal is to appeal to that reader. What would make an eight-year-old want to pick up this book or a 16-year-old read this on the train and not feel it’s too babyish?”

Similarly, says Jon Anderson, president and publisher of Simon & Schuster Children’s Publishing, “We’re always totally focused on making the books look like the people they’re aimed for.” After making a decision to pay more attention to chapter books and middle grade three or four years ago when Anderson saw a glut in YA, S&S now offers as much as 50% more middle grade than YA. To help promote those titles to kids and retailers, S&S created a website, In the Middle Books, with downloadable activities and excerpts. Right now, says Anderson, middle grade is doing phenomenally well.

As for issues regarding kids reading up or adults reading down, booksellers and publishers just want to get the right book get into the right hands. Will there be a time when the distinction between middle grade and YA won’t matter? “I hope not,” says BookPeople’s Goel. “I think there are real differences in how kids and teens view the world.”