First SaaS Customers From a Wizard-of-Oz MVP to $2.5M

"This is not a product," one of his first SaaS customers told him. They were right. Cello had no dashboard, no login portal, and no analytics - just shared Notion pages and Python scripts. But those first paying users still paid because the referral program actually worked. Stefan Bader reveals how he landed his first SaaS customers by turning pre-seed investors into design partners, why success-based pricing removed all early adopter friction, and how a "powered by Cello" casual contact loop now drives nearly 1 million widget opens per month for compounding initial traction. Cello is an all-in-one referral platform powering programs for companies like Miro and Typeform. Stefan bootstrapped from a Wizard-of-Oz MVP to $2.5M ARR and 7 million monthly users. ? Key Lessons ? Turn investors into first SaaS customers: Stefan offered pre-seed round tickets to potential buyers, creating shared financial incentives that converted investors into committed design partners willing to tolerate an unfinished MVP. ?? Ship the Wizard-of-Oz MVP and iterate on what matters: Cello delivered analytics via Notion pages and ran Python scripts behind the scenes. First paying users said "this is not a product" but stayed because results were real. ? Use success-based pricing to remove all friction: Cello charges nothing until referrals generate revenue. This eliminated risk for early adopters and created natural alignment. ? Build a casual contact loop for compounding growth: The "powered by Cello" link reaches nearly 1 million opens per month. Each new customer adds users to the loop, making inbound grow exponentially. ? Lead with proprietary data to land top content partners: Stefan partnered with Kyle Poyar by providing unique referral benchmarks, getting Cello in front of tens of thousands of subscribers without paid sponsorship. Chapters Introduction What Cello does and the problem it solves Revenue, team size, and 7 million monthly users Origin story as CRO at a payment company Building the MVP with compliance and scalability first The Wizard-of-Oz MVP with Notion and Python scripts Freemium success-based pricing for first SaaS customers Building a compounding growth system with growth loops The casual contact loop and "powered by Cello" Content collaborations with Kyle Poyar Network sales and leveraging investors as first SaaS customers Lightning round and book recommendations Resources Full show notes: https://saasclub.io/445 Join 5,000+ SaaS founders: https://saasclub.io/email