That said, the internet is the internet, and one universal rule still almost always applies. "Do NOT send strangers money that you only know from the internet"
Are there exceptions? Of course there are. For instance if you see a well reviewed provider that lives a thousand miles away that you "Just have to see" and you want her to hop on a plane to come see you, well then "one of you" is going to have to shell out some bucks for the ticket and you can bet it's not going to be her.
Never say never, but I honestly can not think of a single circumstance where I could be convinced to send so much as a single dollar, via any method, to a woman I met through SA or WYP. Actually I can't imagine using the WYP platform at all, where you are paying for the privilege of paying some woman to eat a meal at your expense. I don't begrudge buying even a very expensive meal for a lady I am interested in, but I am damn sure not going to pay her to eat it. I know the argument is that "her time" is worth something, to which I STRONLY disagree. A hooker's time is VERY valuable, most hookers make several hundred bucks an hour. A POT SB is most likely a college coed or stuck in a menial job and HER time is worth almost nothing.
It's really not fair to compare TER with SA or WYP, TER is to find reputable providers, SA and WYP are geared for non pros. Don't go looking for Sugar Baby's on TER and don't go looking for hookers on either SA or WYP, although I will concede there is a certain crossover, and what ever you do, DO NOT going sending any of these scammers money in advance of actually meeting.