As a form, fanfictions make intertextuality visible because they rely on readers' ability to see relationships between the fan-writer's stories and the original media sources.
What many people who brush fan fiction off as irrelevant tend to ignore is the vast understanding of a pre-existing setting needed to contextualize the writings made, as well as the effort and organization required to properly build off of such settings.
What they were less likely to say explicitly, but what seemed clear to us, was that fanfiction writing also helped to develop and solidify relationships with various friends, online or otherwise.
Writing, for many, tends to be most rewarding when you can share it with someone. To show others your ability to express thoughts, emotions, and ideas through your use of language is helpful in gaining confidence and experience, and this is even more true when you receive direct criticism as well.
Writing was seen as a way to have fun, exercise one's imagination, and avoid boredom.
English-language learners (ELLs) who affiliated around a common interest in fanfiction--a term for stories that fans of an original work (e.g., Harry Potter) write by using the settings, characters, and plot from the original to imagine and create different situations that sometimes include curious mixes across genres and media.