Kevin Kwan needs to learn when to stop introducing new characters and just focus on the characters he has already written a story about. The cast kept growing, to the story's detriment. 

Many of the characters were not necessary, and by the time the story started to wrap up there were too many plotlines going on to really have a neat ending. Overall, I think this book needed fewer random plot twists thrown in at the end and more time spent making the characters compelling. Also the sheer amount of wealth these people have got nauseating after a while.