Over the years, webmasters have tested literally hundreds of different placements for their AdSense ads to find which ones get the highest click-through rates. Instead of starting your own testing from scratch, it can really help to start with a proven placement and make improvements from there.
Here are four placements that have been proven time and time again with high CTRs.
The "Above the Fold Double Sidebar" Placement
Above the fold, put two small placements in your sidebar. This will basically look like two ads right on top of one another.
This creates the impression that the ads themselves are part of your navigation. Because it's above the fold in places where people are used to looking for navigation bars, your ads get a lot of visibility.
Split test left versus right to see which gets you the highest clicks.
The "Look At This Ad First" Placement
The. ad unit is placed above the content, dead center in the page with no text wrapped around it. In order to read the article, the person has to actually scroll down past the ad.
In other words, they're forced to look at the ad. This generally results in pretty high CTRs.
The "Right Under Top Nav Banner" Placement
People who glance at your top navigation bar are also very likely to see your ad. In fact, some people may even just accidentally click on your ads.
Experiment with text ads versus image ads in this placement. Also experiment with using text links.
The "Inside Content Large Rectangle" Placement
This placement usually doesn't get as high a CTR as the "Look At This Ad First" placement, but it's aesthetically more pleasing to the eye and still performs very well.
It's ideal for sites that want to earn income now, but still want to build a long-term brand. Rather than optimizing just for getting the most clicks possible now, you're getting as many clicks as you can while still building some customer loyalty to your site.
Basically. you place a large rectangle either on the left or right hand side of your page and have the text just wrap around the ad. This gets very high click throughs and looks quite decent.
These are four of the top tried and true placements for getting good CTRs on AdSense. As always, results will vary based on your site and niche, so always split test for yourself.