Prostitution is a separate issue from married women who have affairs.
I expect that most of the women signed up for "Ashley Madison" are busy prostitutes.
Not entirely separate.
The majority men who sign up at Ashley Madison are unlikely to be naive enough to imagine that they will get a fling for free. But they don’t let the risk of getting caught stop them even if Internet arranged rendezvous are only a few steps up from street prostitutes and escort services in terms of confidentiality.
Women who have affairs want to know what they are getting. Few of them will be on a. Internet site because they can’t see what they are getting.
And women who don’t want to get caught absolutely aren’t going to be giving up a credit card number, or logging on from a computer that they are known to have access to.