As expected from a book geared towards a mainstream audience, Free is not as practical as it could be. Most of the book are company stories and economy history. Although they were interesting, I was looking for more detailed data on free business models.
Nevertheless, there were some bits I loved to read like the “How can X be free?” sections (example: “How can everything in a store be free?” about the SampleLab stores), or the list 50 business models built on free. An entertaining book, but don’t expect to create a business model only around its concepts.
I bought the paperback version, but you can read it or hear it for free online.
One of the principles of lean startups is ferocious customer-centric rapid iteration. To validate assumptions, data must be collected from users interacting with the product, a fact frequently forgotten by opinionated developers.
Here are two good presentations about metrics, one about business metrics for startups, and other specifically about web applications design metrics.
Next on my reading list: