Many thanks to Josh Nelson for taking the time to dig further into the available data about web traffic to environmental organization sites. His response to my earlier post makes several excellent points. He's right that Compete.com is an imperfect traffic measure, and he's also right to argue that comparing April 2010 traffic to May 2010 traffic could produce a skewed picture because of Earth Day. It's certainly heartening to see that the March vs May comparison shows nearly all of the Group of Ten's sites gaining traffic (except, oddly, the Sierra Club) and that the overall increase is a respectable 17% rather than a "paltry" (my word) 3%. That said, I still think this is an important topic to explore,...