As a Web Strategist and A/B testing consultant, I’ve worked with everything from Fortune 100 companies to freshly minted start-ups. Regardless of the length of their customer list or the volume of their website traffic, they all ask me the same question: “How long should I run this A/B test for? How long will it take to get accurate results?” It’s a natural question and one that may be even more fundamental if you’re trying to reach a particular quarterly goal for your testing program.  And while I’m not a statistician, I’m not afraid to say that it’s very rare that you’ll be able to conclusively say how long a test will need to run. Continue reading →