alt Hacker NewsErotica is a whole separate class of smut than porn (in the cultural sense, that we understand the term “porn”). It’s literally like calling a book a movie.
It’s also, on the whole, a much more ethical and engaging form of smut. I don’t really have an issue with the choices of consenting adults, but the (video and image) pornography industry is so seldom that.
I've heard that word used to refer to (still) pictures, and in more casual/offhand use to refer to text. I don't understand it as being quite so restricted by media-type as you seem to.