Harper-Collins includes the authors Kay Hooper, Debbie Macomber, and Micheal Crichton. None of my library's OverDrive Harper-Collins books have circulated more than 20 time in the past year. Maybe other libraries have a higher turnover for these books and authors.
Oh, yeah, OverDrive suggests that we re-think allowing people to place holds on Harper-Collins books. Imagine waiting for a book for a month, only to find out it no longer exists!