Opportunity cost A/B testing is a method of comparing two different options to determine the potential loss or gain of choosing one over the other. It involves conducting experiments or trials with two versions of a product, service, or marketing strategy to see which one yields better results. The opportunity cost refers to the potential benefits that could have been gained if the alternative option had been chosen instead. This type of testing allows businesses to make informed decisions by weighing the potential risks and rewards of each option, ultimately maximizing their return on investment.