Correlation Does Not Equal Causation

For fun: Correlation of US State with the number of clicks on online banners | R-statistics blog

Blogger Tal Galili wrote an excellent post demonstrating how simple correlations can be fun to graph and make "good?" headlines but not necessarily reflect what is actually being observed/studied.
He recommend empirical research and a heirarchy of evidence be used to support claims and that that evidence be fact based. click the link above to get the full story.