Important takeaway is they rewrote their website from scratch before even having the A/B testing. Probably one of the best arguments I've ever seen against writing bloated website code. We now know that software can hit a point where it's so slow, that it produces false metrics about its own slowness. Imagine how many people are still out there, who didn't write website B, and are thinking, oh my bounce rate is fine, I don't need to invest money in performance, since the numbers are telling me people don't care. Folks who trust numbers at face value, don't always know what they don't know.