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

Episode notes

"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.