Imagine a big informational multi-functional user-oriented web site. Web team is continually working on improving 1) user experience; 2) usability; 3) page rank; 4) PPC campaign; 5) advertising campaign (radio/TV/newspaper/newsletter/SMM); 6) creative; 7) content. Each above mentioned field is covered in appropriate teams, which have separated and sometimes shared projects and tasks. Traffic changes from time to time, being altered by different projects. We are looking for a method that would allow us to measure traffic accordingly to above mentioned conditions. For example, a month ago I changed the design, and a week ago made up a new PPC campaign. Today, traffic showing is up, but I don't know what caused it – my successful brand new design that I've launched a month ago, but it brought its results just now, or my co-worker's new PPC campaign launched yesterday. Any ideas everybody?
Running A/B tests will help you determine what changes affect conversion. Google's Website Optimizer (http://services.google.com/websiteoptimizer/) is an intriguing program that allows you to test several different versions of the same page to see how they perform. It's important to run this type of A/B test because it eliminates many external factors. Good luck.