Lean Startup
A methodology for product and company development based on Build-Measure-Learn cycles. It advocates launching a minimal viable product quickly, measuring real user responses, and iterating rather than planning at length.
In practice
The core principle of Lean Startup is that business hypotheses must be tested through real experiments, not theoretical market studies. An MVP is not a defective product: it is the smallest version that yields a decisive market insight. Dropbox validated its concept with a simple video before writing a line of code — 70,000 signups in one night. The loop must be run repeatedly until a hypothesis is confirmed or killed.