which, from ur personal experience works best? i use the blend in option, because then visitors mix it with navigation or content and click. myself, when i enter a site and see google ads which stand out, i automatically skip them and never click, because i know it has nothing to do with the site, only annoying however, i clicked hundreds of times ads that mislead me, and i thought it was some link inside the content... anyway, what works for u?
Bright background: Blending Dark blending: Contrasting And when you are into gambling: Put images next to your ads.
I did an unscientific experement and ran a section of my site with contrasting ads for a few months. Then i switched to blended, and CTR increased. Was not a very big change, but it did change..