I can also confirm that changing from white bg with black text to black bg with white text seems to increase CTR not sure it it's a coincidence or not, time will tell.
so the main reason the white-on-black strategy works is because it blends in the ads better and the surfer/visitor is more prone to click the ads that way? it would wreck the readability of the site, but... well, revenue is good
Not necessarily (regarding the "wreck the readility" of the site). I have a forum that is black background against white font. No one has ever complained. People like to blather about how bad something is because it's not the norm; i.e. everything has to be black font against white background, etc. Once people get used to something, they hate to change. They'll eventually get used to your site if they like it enough, and if you have enough to offer for them to stay.
I run into many white on black sites that are just completely unreadable, especially with OS X's text anti-aliasing. A good design can pull it off. So many don't. Right now, white on black stands out. Tomorrow, it might mean "don't take me seriously." Like little stars that follow your cursor or rotating under construction signs.
He's right. I have two sites: My old site has around 450 pages, white background and dark fonts. CTR is 4%. My new site has around 100 pages, dark grey background and white fonts. CTR is 13%. I was wondering why this is so, but now that I found this thread, I'm sure it's because of the background of my site.
I think this true. I see a few blog about celebs. They use a dark background and a colourfull adsense. So the visitor I think will attract by that color. Thanks, after read this, I think I will try it.