Google Website Optimizer
Website Optimizer is a free multivariate testing application from Google. It allows users to test different combinations of content on a site or landing page with the goal of increased conversion rates. It is available to all AdWords users and provides analytic power on par with any website optimization software package out there.
If you are using PPC or email campaigns to drive users to a landing page with the goal of conversion, Website Analyzer is a godsend. Through well thought out landing page design and testing you can get feedback that will significantly impact conversion rates.
By O.J.V at ojvcentral and ojv.no