Early in the A-B craze (optimal shade of blue nonsense), I was talking to someone high up with an online hotel reservation company who was telling me how great A-B testing had been for them. I asked him how they chose stopping point/sample size. He told me experiments continued until they observed a statistically significant difference between the two conditions.
The arithmetic is simple and cheap. Understanding basic intro stats principles, priceless.
The arithmetic is simple and cheap. Understanding basic intro stats principles, priceless.