It all started with Oprah Winfrey. In 1996, she launched a book club that made an enormous impact on readers, authors, and publishers. For fifteen years, Oprah’s choices became worldwide bestsellers. During the heyday of her club,  Oprah’s power as a recommender, often called the “Oprah Effect” in the publishing world, was unparalleled. Michael Pietsch, CEO of Hachette Book Group, said in a USA Today article that Oprah “didn’t originate the idea of book clubs, but more than anyone, she has spread the idea of reading a book as a shared community.” Nora Rawlinson, who’s been the editor of Library Journal, Publishers Weekly, and now EarlyWord, citing surveys showing that “friends’ recommendations are the top reasons people buy a book” says that “Oprah is the ultimate friend to her audience.”

A lot of readers must think they’re friends with actress Emma Watson, because her feminist book club, “Our Shared Shelf”, has 294,000 Instagram followers and 215,000 Goodreads group members. (I’m glad I don’t have to supply the wine and cheese.) Watson, who became famous through her portrayal of brave and brilliant Hermione in the Harry Potter movies, is a United Nations Women Goodwill Ambassador with a special interest in gender equality and its benefits for both men and women. UN Goodwill Ambassadors are celebrity advocates, drawn from the “worlds of art, music, film, sport and literature to highlight key issues.” Recent selections include The Hate U Give by Angie Thomas and The Radium Girls: The Dark Story of America’s Shining Women by Kate Moore.

Actress and producer Reese Witherspoon has even more friends than Emma Watson —  she shares monthly book recommendations with more than 13 million Instagram followers. Here’s what she had to say about her most recent pick, You Think It, I’ll Say It by Curtis Sittenfeld:

This month, we’re reading ‘You Think It, I’ll Say It’ by #CurtisSittenfeld… it’s her first book of short stories! I really loved all the characters in this book. They’re so complex and interesting, and in every story, you’ll find them going through these pivotal moments in their lives. Oh, and my company @hellosunshine is developing a TV series based on this collection of short stories. Can’t wait to hear what you think!

This is what I think: I loved You Think It, I’ll Say It too. (Book clubs, don’t be afraid of short stories! This collection would inspire terrific discussions.) I’m thrilled that Reese is getting on her celebrity soapbox to encourage reading and to support books she loves. I also think that Reese has pretty good taste in books. The cynic in me notices that many of her choices are books that she’s bought the film rights to — so not only does she love them, she has a financial stake in their success. Her “book club” doesn’t seem to engender much meaningful discussion; typical comments on her Instagram posts from her adoring fans are: “She always reads awesome books!”; “Have to get this one!”; “Love this selection. Love love love!”; “Thoughts on reading short stories? Never read a book like this! But it will be a TV series.” These comments are a far cry from Oprah’s hour-long, in-depth televised interviews with authors. But maybe the commenters will read Reese’s selections and discuss them with their book clubs.

As Doubleday publishing executive Todd Doughty points out, celebrity endorsements reach a much larger audience than TV or radio interviews or newspaper reviews: “In previous times, you would have the Oprah or Daily Show bump. Now you have the Reese Witherspoon bump from Instagram.” Vogue magazine calls Witherspoon the “new patron saint of literature”, describing her posts as the “equivalent of an Oprah’s Book Club stamp for the social media generation.” An hour-long author interview with Terry Gross on NPR’s Fresh Air reaches a million listeners, while a photo of Reese holding a book reaches many millions of potential readers. “It’s absolutely something we think about,” says Miriam Parker, an associate publisher at Ecco Books. “We try to get books to people with big social-media followings and are strategic about it.”

Author Adriana Trigiani says, “Book clubs are the best thing that has happened to the world of publishing.” Well . . . according to a Kellogg School of Management study, probably not. Book clubs are the best thing that has happened to Adriana Trigiani. In an Atlantic Monthly article, Professor Nathaniel Garthwaite says that book “endorsements are found to be a business-stealing form of advertising that raises title level sales without increasing the market sales.” In other words, publishing is a zero sum game, with only a finite number of readers. The Atlantic article points out that celebrity recommendations might raise the visibility and sales of particular books, but don’t create thoughtful discussions among readers:

Celebrity-endorsed book clubs don’t actually teach people to make time for and privilege reading within a culture that seems to value speed, visual stimulation, and activity. They endorse “books” more than they do actual reading.

What are your thoughts? Does a celebrity recommendation make you more interested in reading a book? How do you think celebrity book clubs are shaping the literary landscape?