In what was the largest ever first-day sales figure for HarperCollins, Veronica Roth's YA novel Allegiant sold 455,000 copies globally across all formats on its publication day, October 22. The book had an announced two-million-copy first printing.

Anticipation mounted in the month leading to the publication of the final installment in Roth's Divergent trilogy. Preorders set house records, and bookstores across the country hosted midnight publication parties to celebrate the book's release. Despite a handful of readers who, due to a shipping error at Indigo Books in Canada, received copies of the book three weeks early, online spoilers were kept to a minimum until the pub date.

HarperCollins put muscle behind its publicity and marketing efforts, both before and after publication. Roth was met by a sold-out crowd of 800 at the book's kick-off at the 92nd Street Y in New York City on publication day. Twelve hundred attended an evening event on October 23 at the Dallas Barnes and Noble, with fans lining up as early as 4:30 a.m.

The film adaptation of the first book in the series, Divergent, starring Shailene Woodley and Kate Winslet, is slated for release on March 21, 2014.