Dan Norris's book, "The 7 Day Startup," which details the process of launching a successful business within a week. Norris argues that focusing on a quick launch allows entrepreneurs to gather valuable real-world data from paying customers, rather than relying on assumptions. The book emphasizes the importance of creating a minimum viable product (MVP), a basic version of the product or service that allows for immediate testing and feedback. It also explores various marketing strategies for gaining early traction and highlights the importance of building a business model with growth in its DNA. The book provides a framework for evaluating business ideas, choosing a name, building a website, and marketing the business. Finally, it offers 14 key principles for sustaining a successful startup, including the importance of testing assumptions, solving problems as they arise, benchmarking against the best, and focusing on customer retention.