Book reviews on academic blog sites are becoming increasingly visible and important as they give scholars a space to evaluate research and reach a wider audience. While reviews are a familiar genre in academic journals, their similarity to this more recent incarnation is unclear. While it appears to be the same genre with the same purpose to explicitly evaluate a published text and the contribution of its author, the blog book review operates in a very different interactional context. The question arises, then, whether this is the same genre. Does the channel of communication introduce particular communicative constraints and affordances which make this a different kind of text? Based on 30 book reviews in journals and 30 in a respected academic blog, we explore the similarities and differences in reviewers’ use of stance in these two forms. Findings show that all stance resources were employed by both sets of writers but were more frequent in the blog book reviews. The study thus has important implications for understanding the concept of genre, for analysing rhetorical stance choices, and for novice writers embarking on reviewing in new platforms.