(This review is about the "lean methodology" in general, not the book). I would like to echo and add to some of the criticisms here. I've attended a few lean

(This review is about the "lean methodology" in general, not the book). I would like to echo and add to some of the criticisms here. I've attended a few lean startup conferences and read several articles by Mr. Ries as well as Mr. Blank's book. While I believe there are some interesting ideas here and there and also generally a lot of societal value in encouraging entrepreneurs to mitigate risks early on, I think these guys are trying too hard to create a "methodology" out of thin air. Once you get past the few interesting ideas you can borrow for your business, the whole thing just sounds like wishful thinking peppered with pseudo-science. (The difference between pseudo-science and science is rigor and empirical evidence; many things in life "make sense", but don't stand against scrutiny or empirical validation). For example, while it sure sounds reasonable to quantify feature/product usage and quickly respond with rapid product iterations or maybe even a "pivot", in practice you can never determine if the reason people are not using your feature/product is because its execution sucks, or because people don't care about it in general. In scientific terms, correlation isn't causation, and it's really tough to resolve the two. Get these mixed up and you might kill a potentially big product/feature because you didn't try hard enough in the execution. More importantly, to the best of my knowledge none of the giants in the tech world followed anything close to the lean methodology. That includes the founders of Apple, Google, Microsoft, Amazon, etc. Great entrepreneurs have and probably will always be fueled by their beliefs, period. It's hard to imagine Steve Jobs being lean about iPods, iPads, etc. He's failed before, sure, but he's also pushed forward at full steam some of the most awesome and successful products I've ever seen. Perhaps after young Mr. Ries runs an Apple or an Amazon, or after he can back his distracting jargons with empirical evidence I'll pay closer attention to the movement as a general methodology. Until then, I'm perfectly happy with simpler, more down-to-earth precedents like Greg Gianforte's "Bootstrapping your business" (incidentally, Mr. Gianforte has founded and run a billion-dollar company).