I read this book when it first came out, and since the book is such a good read, that made the movie extremely boring. Ofcourse, they have taken a lot of liberties in the movie, like the main charracters fucking each other etc. which does not happen in the book. Also, as for the strippers cashing in, in the book the author mentions, that they knew most of the strippers (and there werent as many as they showed in the movie), since they were regular customers there.
You gotta read the book, and you won't put it down once you start to read it.