The document discusses key principles of Lean UX. It outlines three key success factors: 1) Small, focused teams that are cohesive (Teams); 2) Iterating ideas through testing to allow them to evolve (Memes); and 3) Using metrics to define goals and inform decisions (Metrics). Small teams are more effective due to social factors. Ideas evolve through iterative testing, like memes. Metrics in the form of fitness functions should be clearly defined and measure progress towards goals.