this is all fine and good, but if you're goal is to see what works best between X new versions of a page and you are rigorous in creating variants, Optimizely is a great tool for figuring out the best converting variant.
Except, apparently, they aren't actually that good at _that_. If an A/A test to not yield 100% chance of 18% uplift, what gives you any degree of certainty that other tests won't have equally skewed results?