breeks - 4:28 pm on Mar 11, 2013 (gmt 0)
I think this is more about the ads that are being shown than anything else that is effecting CTR and CPC. Google is deciding what ads visitor sees not the content of the site.
Just like Google search these days Google decides the results based on the user not the search words.
A website about pets might get car ads, car site might get pet ads. So of course CTR sucks.
Some people never clean cookies so we have no Idea what ads they see.