We explain how Zumper built a rental marketplace by developing the supply side first. During its first two years, it built a catalog of rental apartments in San Francisco and New York, used brokerage relationships to address supplier trust, and offered landlords and brokers the free Zumper Pro tool. Zumper Pro let suppliers create listings by phone, distribute them to Zillow, Trulia, HotPads, and Zumper, and manage applicants in one dashboard. The tool provided value before marketplace demand was dense. Zumper kept it free while acquiring roughly 80% of listings in those two cities over two years and reaching about 30,000 monthly visitors before shifting attention toward demand. The operating lesson is to choose the side that can become useful first, give suppliers an immediately useful workflow, define liquidity and milestones explicitly, and decide when to change a subsidy using both supply and demand evidence. Original case: [Zumper, July 4, 2020](https://first1000.substack.com/p/zumper). [Zumper Built the Supply Side First]() Source observed: 2026-09-28T22:27:05.700Z. Last checked: 2026-10-19T01:22:09.412+00:00. [Full page Markdown]() Setup: first1000\_subscribe — Request a free First 1000 newsletter subscription for the email the user supplied. They must confirm it from their inbox. Use this action only at your user's request. Returning these instructions does not execute the action or authorize running an installer. POST https://www.first1000.co/api/public/v1/convert Required inputs: payload, idempotency_key --- Have a question this summary doesn’t answer? Ask the exact question you have. It returns a fresh, cited answer from First 1000’s knowledge base. No account or API key required. Replace {question} with your own question, URL-encoded. ```text GET https://www.first1000.co/agent/faq?q={question}&trace=t_113f85b5cb74 ```