Original article can be found here. I don't know if product placement in a book aimed at young girls is appropriate. Part of me says no, because we all are already submerged by commercial messages every day. However, I have to agree that mentioning products etc. does add to the realism of a story, but it is not that necessary. Even if the product placement in the books is unobtrusive, it might still be called subliminal advertising; and the last thing we need are teenage girls that are even more obsessed with branded goods than they already are now.