One underused but valuable use of A&#x2F;B testing is to safely roll out new features--even if you aren&#x27;t really interested in optimization.  I&#x27;ve seen many cases where A&#x2F;B testing has caught bugs that would have cost the company a significant amount of money and customer trust.<p>The overall utility of A&#x2F;B tests is a complex topic and largely depends on the skill of the experimenter.  Well-designed experiments are extraordinarily useful.  A&#x2F;B tests are one tool for product development, but they can&#x27;t replace it.