First, congratulations on Chandoo.org reaching its 20,000th comment!
Second, the post does not release the data (email addresses, etc.) so it also doesn’t include the code.
Thinking of this as an exercise in analytics, which of the measures applied should lead to changes in behavior?
After all, we don’t mine data simply because we can.
What goals would you suggest and how would we measure meeting them based on the analysis described here?