I don't think there's many that enjoy what they do. Most of them hate men, and no wonder. The vast majority of prostitutes were sexually abused as children, and have a lot of psychological problems as a result.
It always makes me laugh when guys think a hooker gets off on them. It's called giving the customer what he wants -- letting him think he's in control when they're really just faking it. Most guys' egos are enormous and they simply can't comprehend that a woman they PAY for sex isn't getting off on it. It would be funny if it weren't so pathetic.