Step inside the mind of a stalker. That was the first term that came to mind, but don't stalkers usually work from a distance? If so, then David would be different. Peripheral stalking is only a first step. He wants more. He wants to be a part of Veronica's life. 
 As a character, David is pretty well unlikeable. Not a big surprise. I have to believe this was a wholly intentional move by the author. Shitheads aren't supposed to be liked. Supposedly Ted Bundy was a charmer, easily to like, but then again no one had the chance to see just what was going on inside that head of his. It's the outer shell we see, unless you pick up this book. How good is the actor, and how long can he play the part? 
 So when a main character is hard to like, what's of interest? Well, the progression of David's game gets a little intense. I kept waiting (hoping even) for the mistake that would bring down the house of cards he had so carefully constructed along the way. Call me a stalker's stalker, but I wanted to know the outcome. A funny thing happened along the way. As much as I wanted to trip David up, a part of me felt sorry for his nutty self. He's insanely smart, yet weirdly naive at the same time. Add to this the realization that Veronica would have benefited beautifully from a kick to the heiney - the pompous gluteus maximus that she is. Who to root for then? If there's anyone to like, it is Veronica's roommate Sara, the one David uses as a pawn to reach his goal. Collateral damage sucks. 
 Interested so far? Here's another reason to read this book: the final quarter throws a wrench in the works. I had a feeling that something different might be coming. Pretty good ending.