I've never read anything by E.L. James or watched the movies, but from what everyone else says, its not "romance" at all. I have read Avon romances before with a few steamy scenes here and there. My question is, when does "Steamy romance" become "erotica?"
In my view, it's when the sex scenes are the focus of the book. For example, a thriller might have romance elements, but it's not a romance unless the romantic plot is the focus. Any book may have sex scenes of varying degrees of detail, but when those detailed sex scenes (or other erotic content) are the focus of the book then it's erotica.