Owner Bud Burwell, 64, looks over a group incoming used books from a customer at the Reston Used Book Shop in Virginia.

Early next month, Pablo Sierra is opening a used bookstore in Northwest Washington - an unlikely bet in the digital age made even more inconceivable given that his only experience with books is reading them.

"I guess it is pretty crazy," Sierra said, echoing an observation shared by some of his friends.

Or maybe not. Sierra, like other book lovers, has read articles about slowing e-book sales and watched as independent bookstores such as Politics and Prose thrive, catering to readers who value bookish places as cultural hubs and still think the best reading device is paper.

Used bookstores, with their quintessential quirkiness, eclectic inventory and cheap prices, find themselves in the catbird seat as the pendulum eases back toward print. In many cities, that's a de facto position: They're the only book outlets left.

While there are no industry statistics on used-book sales, many stores that survived the initial digital carnage say their sales are rising.

"It gets better and better every year," said Susan Burwell, the co-owner of Reston's Used Book Shop, the only bookstore left for an intellectually diverse Northern Virginia city of nearly 60,000 people.

Riverby Books D.C., a used store on Capitol Hill, closed last year after owner Steve Cymrot was hit by a truck and killed. His son Paul reopened the store in the fall - and didn't hesitate. "The business side of it never gave us a moment's pause," he said. "We've never had better business."

And it's a business with good economics. Used bookstores can beat Amazon on price, offering shoppers both a browsing experience and a money-saving one. Also, profit margins on used books are better than new ones - so good that many indies are quietly adding used sections.

Sensing a good deal, entrepreneurs are jumping in.

Sierra, 38, is a former Navy officer with an MBA and experience in government contracting. His new store, in a small strip mall on Georgia Avenue NW in Park View, is called Walls of Books, a chain started by Gottwals Books in Georgia. The company has opened eight locations since 2012, including one in New Orleans, and offers a training program for owners. The investment is significant:
Start-up costs can approach $85,000.

Shane Gottwals, the chain's co-founder, said some franchisees are fulfilling lifelong dreams to sell books. Others are in it solely for the money. All of them see unmet demand.

"One of the first comments we hear is that the bookstore down the road closed, and there's no place to buy books anymore," Gottwals said. "It's like having a museum or a theater. It's a cultural center. It's a place people want to go. And that's why it's a good investment."

It is by no means an easy business. Many used booksellers - with either bad management or bad locations (or both) - still struggle against the digital headwinds.

For one, Amazon is still just a few clicks away. But some used-bookstore owners have made a shrewd move: widening their customer base by listing their inventories on Amazon's marketplace, an idea many new-book retailers despise. (The Washington Post is owned by Amazon founder Jeffrey Bezos.)

Wonder Book & Video, with three retail locations in Maryland, sells its used books online through Amazon and other retailers. Sales are so strong that it moved into a three-acre distribution center in Frederick, where 4 million used books line row after row of shelves.

It even sells books by the foot, which TV shows and interior designers use for decorating.

And then there's the inventory: Used bookstores rise and fall based on the books they're able to buy. They've been both savvy and lucky in that department.

Savvy: Locating themselves in culturally diverse and book-friendly neighborhoods.

"Everything we have comes from the neighborhood," said Cymrot of Riverby Books, which also has a store in Fredericksburg, Virginia. "Our shops are built on the neighborhoods, and the neighborhoods are full of neat people."

"We get a lot of our best books that way," Burwell said. "People are often sad about leaving their books when they move. I tell them they can visit them until they are sold."

Owners still have to get people in the door. For that, readings and other events have been helpful. Sierra, whose bookstore is in a changing neighborhood with many Hispanic residents, will host bilingual events.

But nothing provides a stronger pull than the experience of browsing - getting lost in the stacks, making serendipitous finds, having chance conversations with interesting people. And with information so easy to find these days, used bookstores offer the thrill of the hunt.

Lori Hamrick, 40, stopped by Reston's Used Book Shop recently. The store, which opened in 1978, is set among shops and restaurants at Lake Anne Plaza. There's an old wooden card catalogue in the corner, with cards tracking store credits for customers. The floor creaks. The stacks are unintentionally whimsical: There's Philip Roth next to Terry Southern.

"I like this," Hamrick said. "I like books."

She was looking for several titles - written in a notebook - in a series of historical fiction called "White Indian" by Donald Clayton Porter, a pseudonym for Noel B. Gerson.

Hamrick nosed around the historical fiction section. Nothing. Drat. On a hunch, she checked in westerns. Bingo. She found book #3, "War Chief," in paperback. She took it home for $1.38.

"I can find these books online, but I don't want to," she said. "It gives you a sense of accomplishment. And if you don't support the little guys, they won't be around anymore."

A buck thirty-eight won't make Burwell and her husband rich, but the economics are good enough for them to pay the bills and do what they love.

Paperbacks, for instance, are bought at 10 percent of their original price, then sold for half the cover price. So they'd buy "Gilead," Marilynne Robinson's Pulitizer Prize-winning novel, for $1.60 (10 percent of $16) and then sell it for $8. That's a 400 percent markup and vastly better than profit margins for new books - or just about any product, for that matter.

Oren Teicher, chief executive of the American Booksellers Association, said "dozens" of independent bookstores around the country are featuring used books, and interest is growing.

Jamie Fiocco, the owner of Flyleaf Books in Chapel Hill, North Carolina, said selling used books - they make up about 6 percent of inventory - gives readers a chance to try a new author for a lower investment. If they find an author they like, they are more likely to buy their next book in hardcover.

And you never know what you'll find in a used book.

Chacko Chakiath, shopping recently at Wonder Book in Gaithersburg, Maryland, said he seeks out books with plenty of notes in the margins.

"You can go, 'What were they thinking here?' " he said. "Or sometimes I have the same issue they had."

Wonder Book staffers find postcards, bills, love letters, prescriptions - markers not just of pages, but the endurance of print.