Which A/B testing methodology is most reliable for determining the optimal placement of a sponsored ad unit on Weather.com's mobile interface?

For determining the optimal placement of a sponsored ad unit on Weather.com's mobile interface, a rigorous A/B testing methodology using a statistically significant sample size and controlling for confounding variables is the most reliable. 'A/B testing' is a method of comparing two versions of a webpage or app element to see which one performs better. In this case, the two versions would be different placements of the ad unit on the mobile interface. 'Statistical significance' means that the observed difference in performance between the two versions is unlikely to be due to chance. A 'confoundi....