It depends on who it is. All in all, I'd say 7.
my grandmother was extremely clairvoyant. I have a little talent. I don't trust most but I did talk to one on the phone once who was so right on it was scary. She actually was freaking out about the guy I was dating even though I didn't tell her anything about him and it turned out she was right.
...I tend to occasionally pre-know things.
But it's pretty random when it happens.
...So, nah, they don't know, which is why I've never asked.
Do you notice how they are so cunning that they'll ask probing questions in such a way that you don't realize that you're giving them the answers. So it doesn't take any smart person that long to piece together those small hints and work out the result. They just tell you what you've already experienced to make you think it's working so you give them more hints and they get paid. :)
A very round zero. Even a vote of one gives them some credence.
Some people are very good at reading the lay of the land... but I'm not keen on paying for advice so I trade.
5, I think they have things to say that you should actually listen to but the rest of the time you should follow your own intuition
0%. However, I have a 100% belief that they are there to make money from me.