Engineeringtalk talks

There is a case study on improving the performance of AdSense. Some of the wisdom includes:

Next, the team experimented with AdSense designs, focusing on optimization through typography and placement. They found the biggest influence on CTR was the similarity between the AdSense type (size and font), and the main body text of the page. The more similar the type, the higher the CTR. The Engineeringtalk team found little difference in CTR between left-versus-right positioning. So they opted for the right side, which proved useful a few months later, when the final piece of the jigsaw arrived - the introduction of link units. After another round of testing, it was no surprise that the link units worked best in the "prime position" as seen on the "heatmap". The new design can be seen here.

Give it a read, there is some good ideas and interesting links from someone who has been successful at making money off AdSense.