"Conclusion: Simplified design improved conversion by an average of 20.45%." is the most important sentence in this post.<p>To be honest you don't have to use Google Website Optimizer to notice that.
There is some "New Math" being invoked here. If the conversion rate goes from 24.4% to 29.6%, it's disingenuous to claim a 21.2% improvement.<p>I stopped at the first misuse of statistics, but by that point, they had taken out informative links from their web site and turned it into a landing page. Frankly, a 5% change in conversion rate is in the noise compared to the effect of targeted advertising (and I have no faith that these sloppy reporters actually did a properly controlled experiment).<p>Edit: Downmodded for asking for real math over marketing math?