With the current demographices u/censorthisss was probably still correct.

A book so empowering and popular everyone bought it for their Kindle/iPad because none of them wanted to openly broadcast they were actually reading it.

When it came out JK Rowling was being interviewed and the topic of 50 Shades came up because it, ironically*, knocked the Harry Potter series off the top of the best seller lists, but for the most part because of the inherent shame most of the buyers had hence prefering to hide their purchase behind the back of a digital device rather than have any paperback or hardback covers showing.

*The irony being that 50 Shades is supposedly 2nd gen fanfic of Harry Potter after the Twilight series was 1st gen even going to far as to cast Cedric Diggory from HP as the lead vampire, which the "writer" for 50 Shades then fanfic'd further turning Twilight into 50 Shades. Meaning the timeline went: Childrens' books > YA tumblr drama > terribly written and unrealistic adult female fantasy porn.

I say "terribly written" not because the story is shit, it is. The literacy involved is that bad at mixing metaphors, literally copy and pasting entire pages over and over when referencing the BDSM contract involved, and other writing that you would expect from uneditorialised highschoolers because it was just that bad in quality, which also then brings up the question just how much proof-reading it got since that was still how bad the final product turned out.