I agree with most of the people in this thread that who is deep and who is shallow is mostly subjective. Someone might find X to be deep while another person will turn around and say that exact same thing is a shallow quality. I consider trading information with people to be something deep, because I'm sharing knowledge and knowledge is power, you know? But someone else, a more emotional person who likes to take things slow and personal might find that idea to be superficial. And actually, my best friend does find that idea to be superficial. So that's an example for you. The best way to be considered deep is to cross the boundary between intellect and intuition.