I find the "lean startup" concept to be humorous. it's like pg's y-combinator essays in MBA-ese. Build an MVP and get users to provide feedback, and iterate like crazy. As long as you're starting from MVP, the rest adheres to the principal of "JFDI". if JFDI is unclear to you, and you're looking at a flowchart to understand what JFDI means in context, then you are probably not going to understand it, ever.