I remember a woman who came to my house twenty years ago. She was selling pre-packaged steaks and meat products — in farm country. She was all charm and compliments until we said no. Then she slammed her briefcase lid closed and huffed out the door with barely a goodbye.

Foolish — if she ever got another job in sales, there's no way I'd buy anything from someone like that.

But there is one thing you have to watch out for when building relationships: getting so friendly they expect a lower rate.

One friend of mine (the narcissist) is a customer who tries to sweet talk salesmen and service people into lower rates. Perhaps sometimes it works, but it's usually all in her head. She said the (younger, married) salesman she bought her car from was "courting" her by taking her to lunch. I said, "Yeah, only he was courting a sale, not you." It proves flattery is a good sales tool. She also says he gave her a 0% interest loan because they really hit it off. Um, I think her 800+ credit score is probably what got her the 0% percent auto loan.