Criticism of others is futile and if you indulge in it often you should be warned that it can be fatal to your career.
Dale CarnegieThousands of salespeople are pounding the pavements today, tired, discouraged and underpaid. Why? Because they are always thinking only of what they want. They don't realize that neither you nor I want to buy anything. If we did, we would go out and buy it. But both of us are eternally interested in solving our problems. And if salespeople can show us how their services or merchandise will help us solve our problems, they won't need to sell us. We'll buy. And customers like to feel that they are buying - not being sold.
Dale CarnegieIf you want to know how to make people shun you and laugh at you behind your back and even despise you, here is the recipe: Never listen to anyone for long. Talk incessantly about yourself. If you have an idea while the other person is talking, don't wait for him or her to finish: bust right in and interrupt in the middle of a sentence.
Dale Carnegie