On page 164 of EntreLeadership by Dave Ramsey he writes,
"Selling and selling properly is not only essential to business but it is also part of life. Henry Ford said, 'Nothing happens until someone sells something.' Ultimately everyone is in sales. All leaders must learn to sell. Selling is part of human interaction. Teachers sell and persuade their students to learn, parents sell their daughters on who to date, spouses sell each other on where to go eat, and in business money is made by selling. No money is made unless and until a sale is made."