Read? Well, yeah. When it's bad, it's very, very bad. Though, I admit, I enjoy a little of the bad stuff just for the camp of it. Most of it's fair-to-middling. But there's some seriously great stuff out there, if you can find it. To my chagrin, most of it is slash of various ratings (
but not all), but I do mean this: at its best, fanfic rises from "entertaining" (which I'll defend to the death as a perfectly worthy goal) to actually having some real artistic merit. So, er, don't be a hata.

Write? Well... yeah. I figure it's in my head anyway; why not use it to get a bit of writing practice in? And:
tiny wrote:It's a nice challenge to explore different aspects of the known material, to play around with possibilities, change some details and develop new consequences from there without bastardizing the characters. I emphasize character depth a lot (partly to try to rehabilitate the fanfiction genre) and try to work out all the details, finish unfinished thoughts, fill holes in the plot, find answers to unanswered questions and so on.
It's a great way to enforce creativity, write inside a clear framework and practice character conceptualization, disposition development and plot development.
Plus I get to work on my favourite tensions between my most beloved characters. *sigh*
QFT. If you ignore the copyright mess, fanfiction's essentially a medium like any other. If you're doing it right, with some actual talent/workmanship, you wind up with something really good.