In order to understand the culture of the physical, virtual, and blended spheres that adolescents inhabit, we build on Gee's concept of affinity spaces. Drawing on our ethnographic research of adolescent literacies related to The Hunger Games novels, the Neopets online game, and The Sims videogames, this article explores the nature of interest-driven writing in these spaces. We argue that fan-based affinity spaces motivate young adults to write because they offer multiple modes of representation, diverse pathways to participation, and an authentic audience. As scholars and educators, we posit that these out-of-school spaces can offer youth new purposes, modes, and tools for their written work. (Contains 1 figure.)