They're definitely young adult and they're definitely very shallow. I did enjoy them when I was fourteen or fifteen, because shallow books really appealed to me at that time and the slight romance did as well. In the end, all I can see the books doing for readers is giving them fashion tips which are about five years outdated now, if not more. I still somehow manage to like the books, even with this review.
I also bought one or two of the Sons of the Dark books a few years ago, which are slightly less shallow.