Here’s another comparison (found at WMW) of Yahoo’s Publishing Network (YPN) and Adsense by someone rotating both on their site (ie every second impression would be getting one or the other ads):
‘I run Adsense and YPN on the homepage of my main site interchangeably to test which is better (equal pageviews at the end of the day, same weights). Both ad networks are both on target, although Adsense ads show more “less sophisticated” adverts (no brand name, mostly mom and pop operations); while YPN shows brand names. Google’s Adsense gives me double digit CTR, while YPN only gives me 1/10 of Adsense’s CTR. At the end of the day, even if YPN gives me higher earnings per click, Google gives me better revenues. It seems that G’s targeting is designed to show what ads fit the page AND what ads are most likely to get click (probably due to some historical data of my target audience or whatnot). On the other hand, YPN only shows what ads can possibly be targeted to the content, but not really designed to generate high click thrus.’
I’ve seen this type of comparison numerous times now – its always the same. Google gets higher CTR, YPN gets high click values. The difference between comparisons though is that for some the lower CTR and higher values of YPN actually turn out to put publishers in a better off position than Adsense. I guess it depends on a number of factors – including the topic of the blog, the positioning of ads etc.
Found via SE Round Table