Michelle Obama’s ‘Becoming’ Editor Starts Her Own Publishing Firm

“When you have a world of massive consolidation and homogeneity, Molly and Sister have a huge passion for new voices,” Ms. Murdoch, the daughter of the media mogul Rupert Murdoch, said.

With her industry experience, Ms. Stern may also have an advantage when it comes to signing authors. During her tenure at Crown, the company published blockbusters like Ernest Cline’s “Ready Player One,” Gillian Flynn’s “Gone Girl” and Andy Weir’s “The Martian,” as well as breakout works of translation like Han Kang’s “The Vegetarian,” which won the Booker International Prize. At Crown, Ms. Stern helped the actress Sarah Jessica Parker start her own literary fiction imprint, an experience she drew on in creating the business model for Zando.

“That’s an advantage she has from being in the business for as long as she has,” said the literary agent David Kuhn. “There will be authors who have worked with Molly in the past who will be much more open to trying something different.”

By aligning authors with cultural ambassadors of sorts, Zando aims to deploy star power to keep its books from drowning in a sea of online content.

“Discoverability is a real crisis,” Ms. Stern said. At Crown, when she was publishing books by lesser-known authors, the lack of broad support was constantly frustrating, even when authors got positive reviews and retail promotion.

“You felt that you were publishing into a vacuum,” she said. “To find an audience is increasingly complicated.”

Several celebrities and public figures, including Jenna Bush Hager, Emma Watson and Reese Witherspoon, have started book clubs and emerged as literary influencers. Ms. Witherspoon’s endorsements helped turn novels like “Little Fires Everywhere” and “Where the Crawdads Sing” into hits, and she has made her media company, Hello Sunshine, into a book-to-screen factory.