“Designing an experiment is like gambling with the devil: Only a random strategy can defeat all his betting systems.” (R. A. Fisher)
These days just about everyone does some form of A/B testing to optimize pages. But asRonald Fisher knew, A/B testing is loaded with traps, and the only way to avoid them is through careful use of randomization and statistics.
There are plenty of free tools out there that make A/B testing easy and accessible, but not all tools are created equal. Google’s Website Optimizer is one of the most complete and polished,