People keen on technology like to focus on how things will work and product people like to dream about what will be. But only companies with a clear sense of why do something are masters of their fate and captains of their efforts. Without a clear story a company is jumping from opportunity to opportunity never really focusing on anything. Therefore articulating purpose of company's existence in the form of mission statement should be high on priority list of any company. A path of a start-up is in many ways similar to growing up of a man. At first you're fascinated by the very fact of your existence, that you can grasp, move, see. Then you get fascinated by others, how they treat you like a person and form relationships with you. Finally, you start questioning your existence and most people find an answer to the question of their purpose through their utility to others, as parents, friends, or professionals. All the most important questions in life start with why and only when you find an answer to them, you become an adult. Similarly, a start-up becomes a grown-up company only when it can justify its existence through its utility to customers.