One of the heat maps Google has displayed in the past shows ads placed on the left with text wrapping around the right. When Google adsense came to my city I sat with one of their reps and she suggested that I move one of my ads from the right over to the left of the article. I tried that and over the next few days I believe it performed worse so I moved it back. Please don't accept that as a definitive test because as you know there are always a lot of factors in these things. I've been making a living with Adsense for three years now and I've always felt like ads placed on the right would do better because people read English from left to right and their eyes continue into the ad when they read to the end of a sentence. However I am a big believer in real and actual data, not just my opinion and personal experience. So when Google says ads perform better when placed on the left, then I certainly listen to them. What is your experience?
I can't take any credit for it. They did that travel around the country thing and I just signed up. What is your experience on the left vs right side question? Any opinion?