In the U.K., Harry Sussex is a prince and a duke. In the U.S., he’s the lord regent of the bestseller list, with his blockbuster Spare—written with J.R. Moehringer—selling nearly 1.2 million copies and taking the crown for top-selling title of the first half of this year at outlets that report to Circana BookScan. But Colleen Hoover remains the bestselling queen. Seven of the writer’s works make up one-third of the top 20 adult titles of the year to date, and are nearing the four million mark in combined sales.

If anyone is to get the credit for shaping this bestseller list, however, it’s the young people on TikTok. In addition to Hoover, Bonnie Garmus, Emily Henry, and Taylor Jenkins Reid all hit the list thanks at least in part to online fervor, with Reid reaching it twice with two backlist titles, BookTok favorite The Seven Husbands of Evelyn Hugo and 2019’s Daisy Jones & the Six, the latter helped into the top 20 by the TV adaptation that hit Amazon Prime in March.

Laura Nowlin took the top spot on the YA list with If He Had Been with Me, another backlist title (from 2013) that benefited mightily from the BookTok treatment. As was the case with the adult list, the author with the #2 bestseller is the real winner, with three books by Holly Jackson netting slots in the top 10, combining for sales of nearly 645,000 copies.

In children’s, the big names remain largely the same as in the past. The latest in Dav Pilkey’s Dog Man series, Twenty Thousand Fleas Under the Sea, was the bestselling children’s book, followed by three perennial contenders: Oh, the Places You’ll Go! by Dr. Seuss, Eric Carle’s The Very Hungry Caterpillar, and Bill Martin’s Brown Bear, Brown Bear, What Do You See? Pilkey and Seuss each had another title in the top 10—the latest in the Dog Man spin-off series Cat Kid and Green Eggs and Ham, respectively—and Jeff Kinney also fought his way in, with his latest Wimpy Kid title, Diper Överlöde.