With the advent of ExactTarget releasing an A/B testing suite and Google Analytics providing the same functionality for websites I thought it would be beneficial to go behind the scenes of what A/B testing really is. Like many real world processes, A/B testing grounds itself in the world of mathematics and more specifically statistics. Don’t get scared away already though, there is hope for all. Many applications simplify the testing process to the point that a marketer, designer, or developer simply selects which is performing better. But what do we mean by performing better? And, why would I want to understand it?