This summer, author Megan Miranda won the publishing lottery.

Miranda, who writes thrillers and young-adult novels, is the kind of author that publishers usually call midlist. She’s well established, and one of her books has even been a New York Times bestseller, yet outside of her genre, she’s not exceptionally famous.

But in June, Miranda published her 10th novel, The Last House Guest, about a murder in an exclusive Maine vacation town. In August, Reese Witherspoon selected it for her book club.

“My editor called me up,” Miranda said by phone a week after the pick was announced, sounding still slightly dazed. “I had just gotten back from my first leg of the book tour when I found out, and I was so ecstatic.”

Miranda was already well aware of Reese’s Book Club before her own anointing. (She “adored” Daisy Jones and the Six, Reese’s March pick, she says.) Writers or people who work in the publishing industry frequently are. Since Reese’s Book Club launched in 2017 in partnership with the actress’s media company, Hello Sunshine, it has become an industry phenomenon with the power to catapult titles to the top of the bestseller lists. And Witherspoon — of Legally Blonde and Big Little Lies and Wild and Cruel Intentions — has become, like Oprah Winfrey before her, one of a select few tastemakers who can launch a book into the stratosphere.

Last September, when Reese’s Book Club picked Where the Crawdads Sing, a debut novel by the unknown 70-year-old author Delia Owens, it pulled the book out of midlist obscurity and put it on the path toward megastardom. Where the Crawdads Sing’s first print run was 27,500 copies; industry tracker NPD BookScan reports that it has since sold over 1.4 million print units, not including ebooks. It has been at the top of the New York Times bestseller list for 52 weeks. Crawdad’s success has only continued in the wake of an article that linked it to a real-life murder, one that allegedly involved Owens’s husband and stepson. (The Reese’s Book Club brand, apparently, is strong enough to withstand a scandal.)

Not every Reese’s Book Club book is a sensation on the level of Where the Crawdads Sing, but all of them are respectable successes. In publishing, a debut novel by an unknown author can sell as few as 3,000 copies and still be doing okay. But Bookscan reports that none of Reese’s Book Club’s 28 picks so far — each adorned with a cheery yellow book club sticker on the cover — has sold fewer than 10,000 print copies.

“This is the equivalent of winning the lottery for these authors,” says Bookscan executive director Kristen McLean.

It certainly was for Miranda. Miranda’s book had a strong start on sales, but by the end of July, the numbers had started to cool. In the week before Witherspoon announced on Instagram that it would be her book club pick for August, The Last House Guest sold just 892 print copies, according to Bookscan. The week after Witherspoon announced her pick, it sold 5,494.

It helps that Reese’s Book Club is a natural extension of the brand of Reese Witherspoon, actress, producer, tastemaker. When Witherspoon tells the book club-loving women of the world that she thinks they’ll love a book, the chances are, they just might.

That’s because Witherspoon has made books, and her own taste in them, fundamental to her image, while appealing to a precise powerful demographic that publishers and booksellers love. The Reese Witherspoon brand is Legally Blonde’s Elle Woods reading a law textbook on a stationary bike; it’s the actress turning Big Little Lies from a book into the 2017 Emmy winner for Best Drama and clutching her trophy with a white-knuckled grip. And it’s that of America’s smart and busy hot mom, casually posing with a book that the other smart and busy women of America will adore — and women, who are 13 percent more likely than men to have read a book in the past 12 months, are the people whose tastes drive publishing.

“There were massive increases”

Reese’s Book Club has a titanic foremother, a giant among book clubs that remains legendary for its ability to make and break authors’ careers: Oprah’s Book Club, which first emerged in 1996 to endorse Jacquelyn Mitchard’s Deep Edge of the Ocean.

Picks for Oprah’s Book Club, announced by Oprah Winfrey on her hit show, regularly sold over a million copies. It helped to build the reputations of authors such as Wally Lamb and Jeffrey Eugenides, and resurfaced older, cherished works by Toni Morrison and William Faulkner for new audiences. She tended to pick books that were aspirational and books that were accessible: An Oprah’s Book Club pick could often be heavy and challenging, and it just as often could be fast-paced and fun to read. Whatever she chose, it soared: When she made Anna Karenina a pick, publishers announced that they were printing 800,000 additional copies.

In publishing, tastemakers like Oprah and Witherspoon are a necessity, both for publishers and for readers. The sheer scale of the industry demands it. More books come out every year than anyone can count — UNESCO estimates that the number is around 2.2 million — so many that it’s easy for anyone trying to keep track of what’s new and worth reading to be buried under the massive weight of the new releases bearing down upon them.

Enter celebrity book clubs.

“It’s clear that Oprah was able to get people to read the book that she picked for her book club,” says economist Craig Garthwaite, who studied the effect of Oprah’s original book club on the industry in 2012. “There were massive increases in the sales of those books.”

Oprah’s Book Club did not, however, convert non-readers. We know this because whenever Oprah announced a new pick, sales across publishing as a whole stayed stable: Exactly as many people bought books as were already going to buy books, no matter what Oprah said.

And not everyone believed Oprah was using her powers for good. In 2001, Jonathan Franzen voiced some qualms when Oprah selected his novel The Corrections for her club, describing some of her previous picks as “schmaltzy” and “one-dimensional.”

For celebrity book club skeptics, Franzen’s argument represents one of the dangers of influencers such as Oprah and Witherspoon. If those books aren’t very good, the argument goes, then Oprah and Witherspoon are leading their acolytes toward mindless pap and lowering the literacy of the American public. But Garthwaite says the numbers suggest that Oprah, at least, was actually pushing readers toward books more challenging than those they would have picked up on their own.

Garthwaite notes that Oprah’s Book Club 2.0, which launched in 2012 with Cheryl Strayed’s Wild and continues today with infrequent updates, hasn’t been able to drive sales nearly as well as her original book club did. “Anything anyone else does, even anything Oprah does,” he says, “is a lot more muted than when Oprah was at her peak.”

Witherspoon, a book influencer of the social media age, of course, is not Oprah. But she’s probably as close to being Oprah as anyone could be right now.

“Nothing but a success”

Witherspoon has been talking about books on her personal Instagram account for years, and her Reese’s Book Club Instagram has existed informally since 2015. But in June 2017, Witherspoon’s production company, Hello Sunshine, took over the club’s day-to-day operations and built a reliable monthly schedule of promotions, interviews, and giveaways. The first “Reese’s Book Club pick” was Gail Honeyman’s Eleanor Oliphant Is Completely Fine, a quirky debut novel about a neurotically controlled woman and her traumatic past.

Witherspoon and Hello Sunshine had already optioned the film rights for Eleanor Oliphant by the time they announced that the title would be their first pick. And that one-two punch of film option and book club drummed up enormous early buzz for the book, says Lindsay Prevette, the executive director of publicity at Honeyman’s US publisher, Pamela Dorman Books.

“That perfect storm really helped the book find its first early readers,” says Prevette. “We could go back to the media and say, ‘Look at how excited Reese is. She really loves this book.’ We could point to Reese’s support and the other books she’s helped over the years, like Big Little Lies.” (Witherspoon co-produced and stars in the HBO adaptation of Liane Moriarty’s 2014 novel.)

Today, if you look at Eleanor Oliphant’s Amazon listing, you’ll see the words “A Reese Witherspoon Book Club Pick” at the very top of the page, in bold, and then a blurb from Witherspoon herself.

“That book did not hit the bestseller list in hardcover,” Prevette points out. But Reese’s Book Club kept working to help it find readers even after Eleanor Oliphant had been out for months: “The book club kept talking about the book on Instagram, building this community of readers throughout the year, a community of fans speaking to each other,” she says. The result? When Eleanor Oliphant came out in paperback in May 2018, it debuted at No. 1 on the New York Times list.

“We’re at over a million copies sold now in all formats,” says Prevette.

The picks that followed — short stories to nonfiction to novels — haven’t all gotten quite that sort of bump, but each has more than a little in common with Honeyman’s hit. So what makes a book a Reese book?

“A woman has to be driving the story”

According to Hello Sunshine CEO Sarah Harden, all of the books selected for Reese’s Book Club are read and approved by Witherspoon herself. “We have a full-time bookworm, someone who’s reading all the time for film and TV and book club,” Harden says. “I read a ton of books as well,” but, she insists, “Reese really picks the books.”

Staff members can pass their recommendations along to Witherspoon to read, or Witherspoon might just bring in the book herself. (While Hello Sunshine’s Harden spoke with Vox, Witherspoon herself declined to comment for this article.) “Our November book pick is something none of us had read,” says Harden. “Reese was like, ‘I just read our book pick,’ and we all then scurried to read it.”

All of the selections are focused on women. “A woman has to be driving the story. They are driving the narrative, they have agency in the story, they are not the side character, they are the one determining how the narrative goes,” says Harden. Witherspoon and her team are not opposed to picking a book written by a male author, as long as the story is centered on a woman. “We just haven’t done it yet.”

Harden says the book club also tries to spotlight works by women of color and international writers who aren’t already well known stateside — and books such as Erotic Stories For Punjabi Widows by Balli Kaur Jaswal, the pick for March 2018. Jaswal, says Harden, is “an incredible author, but only a couple of her books have been published in the US. So almost all of our book club readers were like, ‘Oh my gosh, I love this book, I want to go back and read her other books,’ but they hadn’t heard of her until we picked her.”

“I think Reese really loves that,” Harden continues: “not always picking the book that everyone is already talking about.”

Glancing through the complete list of the Book Club’s selections reveals another commonality: Like Oprah before her, Witherspoon’s picks are always broadly appealing, and they tend to walk the line between literary and commercial. They’re the kind of books that are well written but not too esoteric, fun to read but not so trashy that you might feel guilty about spending time on them. They’re long enough to be immersive, but they’re not doorstops, either.

Publishers tend to even describe these as “book club books” because they feel designed to be read by smart and busy people who want to talk about a good book over a shared plate of hors d’oeuvres and don’t want their reading to feel like a chore.

Once Witherspoon has chosen a book, promotion gets underway. The actress announces each month’s pick herself via her Instagram Stories on her personal account in the first week of every month. Then the book club’s official Instagram account picks up the charge, as does the official book club newsletter. There are author interviews and exclusive essays and giveaways, and readers are invited to share their thoughts about the book on their own Instagrams. But even after a book’s month in the sun is over, the book club isn’t done.

Celeste Ng’s second novel Little Fires Everywhere was selected for September 2017, but it keeps popping up on the Reese’s Book Club Instagram. “We talked about that book when it sold a million copies, and then when the paperback came out. We continued to do giveaways,” Harden says. “That happened to be a book that we also optioned for television, and then we sold that to Hulu, and Kerry Washington and Reese announced they would be starring in it. The show will launch sometime next year on Hulu. So if you’re part of our book club, from September 2017 to sometime in 2020, we’ve had a two-and-a-half-year conversation with you already about that book.”

That long-term approach is one of the benefits of using social media. Oprah orchestrated her book club first through her daytime TV show and later her monthly magazine, which made it impractical to periodically check in on old selections. (Oprah’s current book club is theoretically social media based. She announced earlier this year that she’ll be partnering with Apple to create a new version of her book club, although it remains to be seen exactly what it will look like.)

But Reese’s Book Club is still young enough that it’s an open question whether its long-term partnerships might ever become a liability. When does the club start to look like a crass marketing tool for film and TV projects rather than a genuine expression of love for books? And what happens if a book gets caught in a controversy, as Where the Crawdads Sing did?

Most celebrity book clubs eventually weather such a scandal: when Oprah’s Book Club author James Frey was revealed to have lied in his memoir A Million Little Pieces, Oprah brought him onto her show and made him apologize to her audience for deceiving them, a moment that became emblematic of Oprah’s moral righteousness and insistence that people should be able to trust her.

Reese’s Book Club has yet to make a public statement on the Crawdads controversy, and representatives declined to comment on it for this article. By and large, the Book Club appears to have made the calculation that the best thing it can possibly do is to keep quiet on this issue and hope it will all blow over and that no matter what happens, the controversy won’t affect Witherspoon’s image.

“I just started reading and reading and reading”

The official Reese’s Book Club Instagram is littered with movie stills in which characters Witherspoon has played are seen reading: Annette from Cruel Intentions reading in Central Park; Cecily from The Importance of Being Earnest reading a tiny pocket-sized book while wearing an enormous gown. That’s because Reese Witherspoon nearly always plays driven, bookish women who we see reading onscreen, which is to say characters who we are meant to understand as smart.

Witherspoon’s two most iconic characters are, in fact, iconic specifically for their smarts and their stick-to-it-iveness: Election’s Tracy Flick, who overachieves her way through high school, and Legally Blonde’s Elle Woods, who struts into Harvard Law chirping, “What, like it’s hard?” Witherspoon’s star image is based on the idea of Witherspoon as smart and driven and bookish — in a funny way, a likable way.

And when Witherspoon’s acting career began to falter in the 2010s and she found herself pushed more and more into the mid-tier romantic comedy ghetto, she made books and her own taste as a reader central to her resurgence.

Witherspoon produced the 2014 film adaptation of the novel Gone Girl and was central to the branding of the film: When the rights to the book sold to her production company, Witherspoon was in all the headlines. The same year, Witherspoon produced and starred in Wild, based on the memoir by Cheryl Strayed; the role earned her a second Oscar nomination for Best Actress and a bona fide comeback narrative.

“I just got really inspired and started this production company, started reading voraciously, calling everybody, and material — all of this is born out of a time of great artistic curiosity for me,” Witherspoon said in a 2014 interview with IndieWire. She added, “I funded the whole company myself — purposely, because I didn’t want to be under anyone else’s mandate. I just started reading and reading and reading.”

Reese Witherspoon’s career resurgence is rooted in her taste in books. It depends on her ability to find books about women that audiences will like and respond to, and then bring in trusted collaborators to translate those books for the screen. And audiences are ready to give her credit for that taste because we first fell in love with Witherspoon by watching her play likable smart girls who seemed as though they probably had good taste in books.

It’s like having Elle Woods recommend a book to you. Who’s going to say no to that?

Constance Grady covers books and culture for Vox.

Correction: An earlier version of this article described Hello Sunshine as Reese Witherspoon’s production company. It is a media company.