I have never met a provider in public.
Usually it is wise to act like you don't know each other, but there are circumstances, as some of you have discussed, where you can discretely contact each other, and it works out for good.
Yes, mostly it is all about money, but there are a few escorts who have married hobbyists.
Taking a slightly different slant on the opening question;
Have any of you met/recognized a provider in public whom you had never dated? Did you initiate contact? Did you end up dating?