An ethos around product development that insists on only building products that contribute real value to the world.
“The question is not ‘Can this product be built? In the modern economy, almost any product that can be imagined can be but. The more pertinent questions are ‘Should this product be built?’ and ‘Can we build a sustainable business around this set of products and services?’ To answer those questions, we need a method for systematically breaking down a business plan into its component parts and testing each part empirically” (55, The Lean Startup)
The Lean Startup by Eric Ries