This document outlines five questions to evaluate the viability of a business idea: 1) What is the product/service and does it meet a customer need? 2) What is the business model and is it economically viable? 3) How large is the potential market and what market share could be achieved? 4) How can the business be protected from competitors? 5) What will the founder get personally from the business in terms of money, pride of ownership, and enjoyment? The document provides guidance on thoroughly researching answers to these questions before committing to a new business idea.