Fast

Fast launched their one-click checkout product after observing e-commerce merchants struggling with cart abandonment rates exceeding 70%. ​​‌‌‌‌‌‌‌​‌‌​​‌​​​​​​‌‌​‌‌‌​​​‌‌The team measured genuine interest through conversion metrics on their landing page, which attracted 100,000+ signups within months. Early traction showed merchants integrating Fast's SDK within days of onboarding, with transaction volumes reaching $1 million weekly by their Series A. However, Fast missed critical warning signs: their metrics conflated signup volume with actual merchant retention, and they failed to notice that many integrations came from developers testing the product rather than deploying it to production. The company prioritized growth velocity over unit economics, burning through $120 million in funding while customer acquisition costs remained unsustainably high. When payment processors began scrutinizing their fraud rates and chargebacks spiked, Fast discovered their demand validation had measured curiosity, not sustainable business value. The company shut down in 2022, revealing that impressive early adoption numbers masked fundamental problems with their business model that proper cohort analysis would have exposed earlier.