An excellent way of looking at it: "The goal of the Minimum Viable Product should be to test the founding vision or initial hypothesis. You need to be open to different answers – the answer might be a yes, a qualified yes, or a no. By framing the founding vision like a hypothesis, you remain open to multiple answers."
But don't just have one test for your hypothesis. Have many. Seek to improve your hypothesis.<p>The end result should be an organization with a theory about how it does business. The gift that good founders have that others don't is the knowledge of what that theory was, the key assumptions it makes, and how to tinker with it.<p><a href="http://steveblank.com/2010/05/13/consultants-don%E2%80%99t-pivot-founders-do/" rel="nofollow">http://steveblank.com/2010/05/13/consultants-don%E2%80%99t-p...</a> describes this process very well.
Isn't A/B testing a micro-step of validating your hypothesis? You test your hypothesis and you get certain results. Then you use A/B testing to fine tune your hypothesis and test it even further. Keep tweaking them until you get your desired results. Isn't that how is supposed to work?