" By their very nature, financial analysts tend to be defensive, conservative, and pessimistic. On the other side of the fence are the guys in sales and marketing—aggressive, speculative, and optimistic. They’re always saying, “Let’s do it,” while the bean counters are always cautioning you on why you shouldn’t do it. In any company you need both sides of the equation, because the natural tension between the two groups creates its own system of checks and balances. "

― Lee Iacocca , Iacocca: An Autobiography