There is one burning desire shared by every person you'll ever meet: "the desire to be important," which Carnegie calls "a gnawing and unfaltering human hunger." The winning move is "honest and sincere appreciation," and the losing move is flattery: "One comes from the heart out; the other comes from the teeth out. One is unselfish; the other selfish. One is universally admired; the other universally condemned." He sharpens the difference — "Flattery is telling the other person precisely what he thinks about himself" — and gives the rule behind it: "talk to people about themselves and they will listen for hours."

— In our words · Source: How to Win Friends and Influence People (Dale Carnegie)