- The document discusses various business development processes including subtraction, multiplication, division, task unification, and attribute dependency change as ways to modify a product. It then discusses prototyping and getting customer feedback as important parts of the development process. Specifically, it recommends creating minimum viable products and landing pages to test assumptions with customers before fully developing ideas. The key messages are that business plans should evolve based on customer feedback, prototyping allows early testing of ideas, and pivoting a business model based on learning is normal.