Yeah, some people are incredibly good at telling you what you want to hear. Its mostly because of a combination of saying highly propable and vague things, and a keen eye for your non-verbal reactions. sometimes they even use tricks to get information about you. then these people, the good ones, tend to be very charismatic so just their presence and way of communication is already intriguing. If you're not very educated in recognizing their tricks you'll fall for their sharade.
And lets not forget the placebo effect amazongly proven by - dang forgot his name, a commedian and debunker. He actually told people that he had no psychic powers at the beginning of the show, and then did the whole psychic act, and some people still claim to be healed by him... Now I'm not saying there could not be real miracles, but its always good to go at things with a healthy bit of scepticism and not just believe but thorowly investigate all other possibilities first...