As fandom sheds its longtime stigmas of geekiness and hysteria, fans are demanding more from the celebrities and brands they love. Digital tools have given organizations--from traditional businesses to tech startups--direct, real-time access to their most devoted consumers, and it's easy to forget that this access flows both ways. This is the new "fandom-based economy" a convergence of brand owner and brand consumer. Fan pressures hold more clout than ever before as audiences demand a say in shaping the future of the things they love.

In Superfandom, Zoe Fraade-Blanar and...