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.