Good for a one time watch

Lets be honest, if there were no hot women in this movie hardly anybody would want to watch it. But I think the idea is good. Using the webcam theme was well done. However the killing happened more towards the end. I couldn't understand how the killer adopted this trait. And how could any college student want to do web cam shows? Wouldn't she be be recognised by any other fellow students?
Besides this the film is a one time watch.