James Agres, founder of 2nd St Strategy, sheds light on the pivotal role of market sizing in commercial diligence. He breaks down essential terminologies like TAM, SAM, and SOM using relatable examples, such as a barbershop business. Agres explains the importance of understanding market dynamics and competitive analysis to identify valuable opportunities. He also discusses methodologies for various industries, including software and healthcare, showcasing how precise market assessments drive better business decisions.