Hi, i just found and joined this site: http://www.alternateurl.com/ it promises to fill up my content bars from adsense with more relevant ads when google has only got a few ads. Or as they state it: I will try this program out (if some other people could try it also out together with me) so we can make a review on how it affects our ratios and earnings. I will post updates here as soon as i see some traffic! ps i got approoved in only 1 hour!
I signed up for it but descided that the ads looked like crap and where totally unrelated to the topic of the site, I'd rather show nothing or affiliate links.
I would consider such things if I ever had topics with no ads in them.. I haven't experienced that yet.. Pretty much all the sites I have adsense on have more than enough ads to fill out their space. And when they don't I have a banner ad of myself to pick up hot chicks.
I received a response to my concerns about from AlternateURL, again I have posted it at my blog. Basically, they said they are working at getting color customization and better targeting.