Fandom's definition--and thus the usage which may appear in my journal--of "an intent to arouse" is, I think, very complicated, with the line between sexual and other types of arousement/pleasure being very blurred (that's what slashers do, blur that line), and insofar as sexual arousement can be separated from, say, "literary" arousement, the word "porn" doesn't seem to be used to apply only to the former.