I saw those ads this summer when we were looking for a rental.
One scammer claimed to have “lists” of pet approved housing that you purchased from them. Apparently the list was outdated and none of the properties were available any longer.
I know this because someone was on the war-path and kept taking out their own ads outing the scammers.
The other one was the one I think you are talking about with the crazy low ball price and one pic on each ad. I think it is the same scam where they claim to have a list that you purchase. A list of outdated listings or ones you could have found yourself on craigslist.