People are doing sadder things than this to keep the emotional lights on. At least it's cheaper than prostitutes.
You know the saddest first-world thing I've ever heard? A prostitute doing a reddit AMA had a client once that wanted her to sing "happy birthday" for him. It was his birthday and no one else was going to.
That's rather broad. There are moral issues with sex slavery, for instance, but prostitution as a concept is fairly amoral unless you mistakenly believe the sexuality of others is something you have a right to judge.
