As marketers, we constantly strive to improve our results. And when it comes to learning – and proving – efficacy, something as simple as A/B testing is paramount. A/B testing, the process of using two versions of a marketing piece (web page, email, etc.) to see which one performs better, offers us the ability to tweak very small details in our programs to see incrementally larger results. But, like many marketing strategies, A/B testing can provide mixed, or even inaccurate results if not properly executed.