Lean Startup is a methodology designed to get companies to adopt a Build, Measure, Learn product development cycle. This emphasizes that teams quickly build an MVP (Minimum Viable Product) of a new product, measure how it performs, and learn from the experiment. The goal is to quickly go through this cycle to maximize learning and reduce costs in a short amount of time. The end result, ideally, is a more effective and agile company. (kissmetrics.com)