Prostitution is defined to be sex in exchange of consideration
The term "prostitution" generally means the commission by a person of any natural or unnatural sexual act, deviate sexual intercourse, or sexual contact for monetary consideration or other thing of value.
The problem is what sort of consideration count as prostitution?
Imagine a girl saying that I only want to have sex if we're married. That is a consideration. It has value. Is she a prostitute? Most of us wouldn't think so.
Imagine a girl saying, I only want to have sex if I get bitcoins. She's not getting paid. She's getting something else. Is she a prostitute?
So what's the limit?
What counts as consideration?