Reading through some of the posts on Pro Blogger about 31 days to building a better Blog I am stumbling on some very interesting content. Salman Siddiqui writes about: Earn “6 Times” More With Your AdSense Very Easily. This articles raises a key point to success using Adsense.
The article explains some of the process involved with Adsense:
The publishers bid in Google AdWords to get to the top in your blog pages where Ad Units are displayed. The theory is simple. The one who pays out more has more chances to be displayed at the top in the pages running ads. So the first Ad unit in your blog page will display the advertisers which pay the highest for clicks, the second Ad unit pays out lesser than the first and so on.
Salman suggests that using some logic based on the information above, the first ad displayed on your page will have the ads that pay out the most. So if you only display one ad unit the clicks that you get through Adsense will pay out more. I am guessing that you will want to place the one ad unit very carefully, but the logic sounds solid to me.
I am currently not running Adsense on this blog, but I would be interested to hear what other people think about this theory.