Optimizely did an A/B test that showed that customers respond better to rounded-up numbers. ;-) the real world is messy. Years ago my team's statistician did a

Optimizely did an A/B test that showed that customers respond better to rounded-up numbers. ;-) the real world is messy. Years ago my team's statistician did a competitive review of various AB test apps, and reported various ways in which the UIs make statistically invalid statements to the user.