This document provides teaching notes for mentors on revenue streams and models. It instructs mentors to ensure student teams are making progress on their hypotheses and discovery work. Mentors should focus critiques on student understanding of customer relationships. Common student mistakes include not understanding differences between customer acquisition and activation, as well as the importance of online marketing even for physical products. Mentors should emphasize the key components of revenue streams like types, models, pricing tactics, and differences between physical and digital models.