From a Wall Street Journal story by Ellen Gamerman and Ashley Wong headlined “Cracking Colleen Hoover’s Bestselling Formula”:

In book clubs and on social media, at libraries fielding hold requests and through the ranks of publishing houses marveling at her 20 million copies sold worldwide, people want to know: How does Colleen Hoover do it?

Ms. Hoover, 42, stands at the helm of a massive book-publishing empire that spans thrillers, coming-of-age stories and romance. With the help of fans who call themselves CoHorts, her books—initially self-published and now released by the Simon & Schuster imprint Atria and other publishers—dominate the New York Times paperback bestseller list, currently occupying eight of the top 15 spots. On social media, readers often show off heavily annotated copies while swooning over their “book boyfriends” from her stories and sharing emotional time-lapses of themselves reading her novels.

From a New York Times Inside the Best-Seller List story by Elizabeth Egan headlined “When Writing a Future Best-Seller, Give It Room to Breathe”:

Nina de Gramont is the author of eight books — four for young adult readers and four for grown-ups — but her latest novel, “The Christie Affair,” is her first New York Times best seller. “If this had happened when I was 25, I’d think that it meant I was really brilliant,” she said. “Happening at 55, I know it means I’m really lucky. So I’m appreciating it, for sure.”