This article examines ‘adaptability’ (Verschueren, 1999) as manifest in online consumer reviews, a progressively popular and non-trivial mode of computer-mediated communication which has so far attracted little interest among linguists of various orientations. It centers on genre dynamics in reviews of linguistics textbooks, which lie at the nexus of academic and promotional genres and covers an inquiry of audience design and efforts to socially authenticate reviewer personae. On top of the technological and communicative affordances of the retail site, the author presents a concept of ‘pragmatic’ affordances, tied to the ingredients of Verschueren's pragmatic theory of adaptability, i.e., its locus, processes and status. The article raises the comprehension of language as an adaptive tool in self-commodifying online environments.