Validate that a startup idea has real market demand before building. Use when the user wants to check if an idea is worth pursuing, is worried a competitor already exists, or asks "is this a good idea," "should I build this," "someone already built my idea," "how do I validate an idea," or "how do I know if there's demand." Covers the demand-first mindset, the four failure modes that kill bootstrapped ideas, and the competitor reality check. For finding ideas from your own background, see founder-market-fit. For researching demand signals, see trend-research.
