I think search traffic and type-in traffic are suitable for adsense clicks.. But I think viral marketing helps people learn what is adsense, what is main content; so clicking would be less likely. Is this correct? (so viral marketing=buzz is not equally vauable). Also introducing your site to public or explain in detail how it works, would have the same effect. No experience, just guessing.. BTW why am I red again??
The english might be a bit poor...but I believe he is asking if Adsense is more successful on sites with lots of SE traffic or on sites that are viral / offline promoted.
I have noticed that Yahoo traffic has a higher CTR than Google traffic, and that MSN traffic has a higher CTR than both of them. I have also noticed that Slashdot traffic has a very low CTR.
That's because slashdot and digg people know about Adsense so they tend to ignore it. Unless it is extremely relevant (ad) they will ignore adsense.