“The Lean Startup has a kind of inexorable logic, and Ries’ recommendations come as a bracing slap in the face to would-be tech moguls: Test your ideas before you bet the bank on them. Don’t listen to what focus groups say; watch what your customers do. Start with a modest offering and build on the aspects of it that prove valuable. Expect to get it wrong, and stay flexible (and solvent) enough to try again and again until you get it right. It’s a message that rings true to grizzled startup vets who got burned in the Great Bubble and to young filmgoers who left The Social Network with visions of young Zuckerberg dancing in their heads. It resonates with Web entrepreneurs blessed with worldwide reach and open source code. It’s the perfect philosophy for an era of limited resources, when the noun optimism is necessarily preceded by the adjective cautious.” —Wired