I've heard this a lot over the years: that leaving Adsense ads off pages that generate a low CTR will improve your bottom line. Is this one of the Adsense urban myths or is there some substance to it?
I noticed that the good folk at Adsense recently started sending out tips again -- more specific but also somewhat crptic. Mine was that I could be earning more if I allowed Adsense ads on the 43% of my site that is currently (according to their reckoning) Adsense-free. I'm not sure what this 43% is referring to because certainly over 90% of my (one-and-only) site's pages carry Adsense script. Maybe it refers to file size, or some other measure.
Which brings me to my point. I don't have Adsense on some very large (in terms of word count) pages on my site -- including my home page -- simply because they are so diverse in content that they result in poorly targeted ads and hence low CTR. But am I leaving "money on the table" or am I being smart by not having my whole site penalized for having a lower overall CTR?