Alternate Character Interpretation: Tizzy at first just seems shy and a bit flighty, but the last time we see her in the book, she gives Audrey a T-shirt that says "I liked you better before you sold out". Whether it was meant as a joke or not, we may never know.
Unintentional Period Piece: Aside from a couple of mentions of MySpace, social media is nonexistent, and most people listen to music in the form of CDs or MP3s, with one climactic scene taking place in a record store.