Sarah Tavel's framework for building marketplaces that actually stick. The counterintuitive move is starting small: constrain to a "thimble" market until you hit minimum viable happiness on both sides, tip that market to saturation, then expand. Most founders chase GMV growth too early and end up with leaky buckets. Use this when launching a two-sided marketplace, diagnosing retention problems, or deciding if you're ready to expand geographically. The framework pushes you to track "happy GMV" instead of vanity metrics. If you're facing the classic chicken-and-egg problem or wondering why your marketplace hasn't reached escape velocity despite decent top-line numbers, this gives you a clear sequencing playbook.
npx skills add https://github.com/pmprompt/claude-plugin-product-management --skill hierarchy-of-marketplaces