[This is part of the Blogger’s Guide to Earning More with Google Adsense.]
One of the challenges that you might encounter for A/B Testing is that of bias. In other words, you might discover (or feel) like there were too many other factors that were introduced to get a complete understanding of the original test.
For instance, you may have redone the design of the blog in addition to changing the locations in your split test which could have contributed greatly to the increase or decrease CTR.
The answer? Real-time testing. The Google Tool introduced in the last post does a good job of this but it may take a bit of time to get installed and up and running. Another way, especially with WordPress, is to use a little code to simulate the A/B test.
You can do this quite easily with the following PHP code: