Which blog design works better with AdSense, a two-column or three-column design?
My experience says to use the three-column design.
But specifically, use a three-column design like the one I'm using on this blog. I have two columns on the left, the first to hold "about us" information, and navigational links. The second to hold advertising.
I've experimented with various blog designs, including two-column designs, ones with the content on left, and ones with the content on the right. Right-sided content placement, with ads on the left, always seem to produce higher click through rates for AdSense.
I think the explanation for this is because people in the western world read everything from left-to-right, and from top-to-bottom. Hence, if you have ads on the left, people will glance over them quickly as their eyes come to rest on the content.
So, why would a three-column design produce higher click-through rates for AdSense, as opposed to two-column? I don't know exactly! I do know that when I look at a two-column blog and compare it a three-column, I find myself looking at the material in the middle column more often. Perhaps the eyes and brain are trained to believe that the column in the middle is always important, while the outside areas are less important.
Two years ago, I wrote an article on the very same subject, and published it on In Your Web...
Except on this article I said to place the content on the far left, and the two columns on the right. I went on to say that this produces more clicks on AdSense. However, in the two years since I wrote that article, I'm discovering the opposite is true, to place the content on the right, and the two other columns on the left!
Just goes to show that I'm constantly learning as I go along.