This paper explores ‘adaptability’ (Verschueren, 1999) as manifest inonline consumer reviews, an increasingly popular and non-trivial mode ofcomputer-mediated communication which has so far attracted little interestamong linguists of various orientations (but see Vásquez, 2014). The focus is ongenre dynamics in reviews of linguistics textbooks, which lie at the nexus ofacademic and promotional genres. As writers of reviews will have to grapplewith some degree of ‘context collapse’ (Marwick and boyd, 2010), the articleincludes an investigation of audience design and efforts to sociallyauthenticate reviewer personae. Findings indicate a major divide in the databetween topic-oriented and author-oriented reviews. In contrast, audience-orientedreviews are practically missing; rather, imagined audiences tend to appear inthe texts implicitly as similar to the reviewer, suggesting conceptions of amass audience as well as specific groupings of general audiences. On top of thetechnological and communicative affordances of the retail site, I propose anotion of ‘pragmatic’ affordances, tied to the ingredients of Verschueren’spragmatic theory of adaptability, i.e., its locus, processes and status. Thestudy increases the understanding of language as an adaptive tool inself-commodifying online environments.