Starting with the a/b split testing going on here. As said we are using Google Website Optimizer to do this and it’s free. What it basically does is, it tests two or more different copies of your webpage where one copy is page a and the other is page b, hence a/b split testing
The idea is to make minor changes and test for difference in results. You can optimize by taking the best performing one and split tests it again until you drop or until there is simply no optimizing needed anymore…which is doubtful considering that the internet landscape keeps changing all the time! There is also a multi variant testing feature but, for most the a/b testing will be sufficient enough.