Long time geek, fangirl, mother, and reader. I've got a lot to say, you might not like it all, but it will be honest and hopefully helpful.
"Unlike any other fanfiction fandom, and certainly unlike any children’s franchise, Twilight not only inspired an underground erotic romance revolution but took it mainstream."
I'm fascinate by the misleading phrasing of this sentence. Harry Potter fandom (among others) is based on a children's franchise and has as much erotic fan fic. It also launched a best selling book series. Though the Cassie Clare's Mortal Instruments series didn't have the same kind of mainstream success Fifty Shades of Grey has had.
Then again, neither have any of the other published fan fics coming out of the Twilight fandom.