Unimpressive books fail to make effective, distinctive, or otherwise substantive contributions. Yet their reviews can be useful to potential readers (as caveats), to publishers (as quality-control checks), to authors working on similar book projects (as models of what to avoid), and even to the reviewers themselves (as exercises for developing connoisseurship within a specific field). By articulating the implications and transferability of evaluative criteria, this essay explores the value and utility of such reviews.