Young fanfiction writers use the Internet to build networks of reading, writing and editing--literacy practices that are highly valued in schools, universities and workplaces. While prior research shows that online spaces frame multiple kinds of participation as legitimate, much of this work focuses on the extensive contributions of exceptional young authors. In this paper, we foreground the contributions of fanfiction reviewers and focus on their interactions with writers, exploring their communicative literacy practices and hypothesising about how we can make their reading and writing more visible and more effectively consider their learning practices. To do so, we conducted a linguistic analysis of fanfiction review comments on two sites, FanFiction.net and Figment.com. While fanfiction readers provide writers with an authentic audience for their creative work, our findings indicate that the review comments that they leave generally do not offer specific feedback regarding the craft of writing. For this reason, we argue that teachers' expertise is still needed in the difficult task of developing young adults' composition, peer review and critique skills.