Does the CTR on your adsense banners effect whether PSA's are displayed or not? Trying to work out why my blog is displaying them; none of the reasons Google suggest in the Help explain it. *sigh*
Yes it does. When a PSA's ad is shown it is counted as a impression/pageview. If you have lots of PSA's it will lower your ctr in the end.
Sorry, I meant the other way around: if you have a low CTR, do they "give up" on you and just show PSA's?
Dont think they will. The fact that you get PSA ads isnt related with low ctr, is it? Did you read about Public service ads on Google's website?