The document discusses how building a startup around a mission or cause can help drive growth. It uses the example of Transferwise, which was started to solve the problem of high fees for international money transfers. The mission of Transferwise is to make money transfers fast, cheap, and easy worldwide. The document emphasizes that evangelism and inspiring customers with the company's mission are major drivers of growth for Transferwise. It has grown from a few employees transferring small amounts to hundreds of employees transferring over $1 billion per day and saving customers over $1 million daily in fees.