"The Lean Startup" by Eric Ries is a B-tier book that offers valuable insights for entrepreneurs, particularly those looking to develop a tech-based company. It provides a fresh perspective on entrepreneurship and introduces practical strategies that can be implemented immediately. However, its direct applicability may be more limited to the technology sector than general business, but it should not be discarded as only a tech book.

The book offers solid guidance on continuous learning, rapid experimentation, and iterative product development. It emphasizes the importance of testing hypotheses, gathering real-world feedback, and making data-driven decisions. These principles align well with the dynamic nature of tech startups and the need for constant innovation and adaptation.

Here is a quick list of notes to help you.

“Build-Measure-Learn" Feedback Loop: This concept emphasizes the importance of rapidly building a minimum viable product (MVP) and launching it to gather valuable customer feedback. By measuring the impact of the product and learning from the feedback, startups can make data-driven decisions and iterate on their products to better meet customer needs.

Innovation Accounting: This concept focuses on measuring the progress of a startup beyond traditional financial metrics. It encourages the use of actionable and objective metrics, such as customer acquisition rates, activation rates, and retention rates, to track the success and viability of a business. By prioritizing learning over vanity metrics, startups can make better-informed decisions and allocate resources effectively.

Continuous Deployment: This concept promotes a culture of frequent product updates and releases. Startups are encouraged to rapidly deploy new features and improvements, gathering feedback and learning from each iteration. By embracing continuous deployment, startups can adapt to customer needs more effectively and minimize the time and resources wasted on building products that may not resonate with the market.

Customer-Centric Approach: The book highlights the significance of customer-centricity and engaging with customers early on. By deeply understanding and addressing market needs, entrepreneurs can build products that resonate with their target audience and increase their chances of success.

While the book’s focus is more niche towards apps and tech, there are still valuable takeaways for entrepreneurs in general businesses. The customer-centric approach, emphasis on market validation, and practical tools like the "Build-Measure-Learn" feedback loop can be applied across industries. These insights can help entrepreneurs refine their product-market fit, improve customer satisfaction, and make informed business decisions.

In conclusion, "The Lean Startup" is a worthwhile read if you're seeking new perspectives on entrepreneurship or looking to develop a tech-based company. It provides practical strategies and valuable insights for entrepreneurs in general business as well, although some adaptation may be necessary. While it may not be an A-Tier book with broad applicability, it offers solid value and can inspire innovative thinking and a customer-centric approach to business.