Having done my fair share of banner advertising, I've long been familiar with the extremely poor performance of banner advertising. A thread in the IMR forums, Banner CTR, brought this topic up, and soon the conversation turned to Adsense CTR vs Banner CTR.
Although it's too early in the morning to put serious thought into it, I'm guessing that the Google CTR's are significantly higher due to the fact that Google's ads are specifically relevant to the topic of the page, whereas banner advertising tends to be more generally relevant to the website topic.
Whatever the reason be, Google has done a magnificent job of restoring the old 468 by 60 dimension to its previous glory.
