Design an Experiment to Validate a New Pricing Model

To validate a new pricing model for a live service, I would first clarify the hypothesis: does a tiered structure increase ARPU without disproportionately increasing churn among small developers? I'd define success by a net positive impact on Lifetime Value, while strictly monitoring guardrails like API error rates and refund requests. The approach would be a randomized A/B test, but given the critical nature of payments, I'd start with a 5% traffic split, focusing on low-risk segments like free-tier users before expanding. We must ensure the randomization is consistent across sessions to avoid user confusion. Crucially, I would implement a 'circuit breaker' mechanism; if the control group's churn spikes more than 0.5% relative to the treatment group within 48 hours, the test auto-rolls back immediately. I'd also plan a post-test qualitative analysis via user interviews to understand sentiment behind the numbers. This ensures we capture both quantitative performance and qualitative trust signals essential for a platform like Stripe.