My wife tell me that in the 1960s and 70s growing up in Jarabacoa she remembers at least 3 whorehouses, one with a block of whre she lived. There were almost no foreign tourists in those days.
I can tell you back in the Seventies, this country was saturated with "Casas de Citas" and whore bars. This is not second hand info... I personally saw and visited many of them.
There was no way one could begin to count how many there were in Santo Domingo, but I'd guess easily over a hundred. Go into Villa Juanita today and see how many you can find. (Hint: A lot)
One of the more famous Casas was run by a woman named Australia, who specialized in underage virgins.
Her husband was a General, and most of her clients were high ranking officials in the government (Police, Military, politicians)
No gringos around back then - all of them catered to Dominicans.
What happened? The internet. No doubt in my mind.