Fandoms
We wouldn't say Harry Potter has "fans" so much as…devotees? Followers? Worshipers? Apostles?
You get the drift: The folks who love Harry are intense about it, as we've already discussed (a lot) in our guide to Harry Potter and the Sorcerer's Stone.
And hey, they're still making movies (and plays !) inspired by the Potterverse, so it doesn't look like the fandom is dying down any time soon.