I know they might not be able to tell you your future but to me, they are just another form of psychiatric doctors and use different way to give you hints on which direction you can go. Sometimes when the stuff I already talked to my wife but she would not listen but when the lady told her, she would at least consider to think about it. Maybe advice from third party is more helpful.
I think this is a bit different from selling 風水 products.
But the thing is sometimes you might not have the enough confidence to believe in yourself and you need someone other than the people you know to tell you that.