Their methodology is bad. The most effective CPCs are the ones that do not look like ads, therefore, are not representing accurately what a person is clicking on. A better approach would be to compare the different designs that LOOK LIKE ADS, and test which one is most effective.

>The small logo set also included the most popular ad from this entire experiment. Which is one of my favorite pieces of stock photography and can be seen below...

The above statement confirms that choice in creative can have a tremendous impact. Each of their "myths" can be adjusted using effective creative.