In March 2015, British singer Sam Smith took to Instagram to tell his 3.6 million followers that one woman, Amelia Freer, had changed his life with her book, Eat. Nourish. Glow., which he credited with his recent weight loss.

Published by Harper UK imprint Harper Thorsons in January 2015, the book exploded after the Grammy winner’s endorsement, and with no editions available in the States, Harper turned to Harper360, a program designed to publish English-language titles globally, to meet the sudden demand in the U.S. The paperback was released in the U.S. on April 14 and hit PW’s bestseller list on April 27.

The effect of Sam Smith’s [post] was positively seismic, catapulting Amelia to the number-one slot on Amazon overnight, and effectively wiping Harper UK out of all stock within 48 hours,” said Victoria Comella, director of publicity at Harper360. “This was in spite of the fact they had literally just signed off a reprint of 10,000 copies.”

In Eat Nourish Glow, a hybrid between a lifestyle book and a cookbook, nutritional therapist Freer lays out 10 steps to weight loss and overall wellness, in addition to offering more than 25 recipes. Since its release, Harper Thorsons now has more than 200,000 copies of the title in print across all territories, and it became the number one–selling cookbook in the U.K.

After Smith sent the book soaring up the charts, Harper, on the corporate level, looped back and acquired U.S. rights in mid-March, and then used the 360 program to get the book to the American market as quickly as possible: the e-book was available for sale within 24 hours, and the physical book on preorder within 72 hours. “360’s regular remit is to publish books from our affiliate companies in the U.S. where U.S. rights already exist,” said Comella. “But this was indeed a special case.”

On June 9, Harper imprint HarperWave will take over publication of the book in the U.S. In the meantime, the British author came to the U.S. to build yet more momentum—she was in New York the week of April 27 for a full media lineup, appearing on the Today show on April 29.

Harper launched Harper360 in the U.S. in June 2012, and, at the time, the publisher stated that the inspiration behind the program was that the Harper global catalogue was “limited only by the rights held, not by technology or geography.” In May 2013, Harper360 expanded into the U.K. Since its inception, 360 has published approximately 1,200 books through its U.K., Canadian, Australian, and Indian affiliates.

“This whole experience with the success of Eat, Nourish, Glow has been a real testament to the importance of Harper360,” said Comella, “And the need for the industry to think globally when it comes to the publishing landscape.

A condensed version of this article appeared in the May 4, 2015 issue of Publishers Weekly.