Why Your A-B Test Changes Don't Move the Needle

Episode 30 of Conversion Rate Optimization with Fexingo. Lucas and Luna tackle one of the most frustrating problems in CRO: you run a textbook A-B test, get a statistically significant winner, implement it, and nothing happens to overall revenue. They break down the 'dilution effect' — a concept from multi-armed bandit theory — using Amazon's real-world experience with search result page tests. You'll learn why small changes in low-traffic areas rarely move aggregate metrics, how to identify tests that can actually move the needle, and why Amazon rerouted its entire testing philosophy around this one insight. No theory without application: they walk through a specific 2025 example from a mid-market e-commerce site that wasted six months on a test that was never going to matter. #ConversionRateOptimization #ABTesting #DilutionEffect #Amazon #CROStrategy #MultiArmedBandit #StatisticalSignificance #Ecommerce #Marketing #FexingoBusiness #BusinessPodcast #DataDriven #Experimentation #Productivity #WebAnalytics #UserExperience #LandingPage #TestDesign Keep every episode free: buymeacoffee.com/fexingo