Dan Martell, a former rehab resident turned millionaire at 27, shares his powerful insights on starting a business without any cash. He lays out seven essential steps for launching a zero-cost venture, including choosing profitable models and pinpointing customer pain points. Martell emphasizes reliability in delivering promises and harnessing word-of-mouth marketing for growth. He also discusses the importance of cash flow management, strategic hiring, and developing talent to ensure lasting success in business.