Suppose you’re planning to run a simple A/B test on a Web page and you’d like to use bounce rate as your measure of success. Can you do it with Google Website Optimizer (GWO)?
I’ve had this issue crop up a number of times recently, so I decided to research it. Here’s what I found out.
Can I set bounce rate as a conversion goal within GWO?
No. GWO itself does not report bounce rate, nor does it allow bounce rate to be set as a conversion goal. It’s possible to approximate bounce rate as a goal by coding every single link click on every single experiment page as a conversion event, but that gives you exit rate, not bounce rate - plus the setup can take a lot of effort.
Can I get bounce rate for GWO A/B test variations from Google Analytics or Omniture?
Yes. Although bounce rate isn’t reported within GWO, you can get it from Web analytics tools such as Google Analytics and Omniture. Integrating the data turns out to be very easy, and in fact requires zero coding as long as all experiment pages contain your standard Web analytics page tags.
Here’s why it’s easy: As GWO serves variations in an A/B test, visitors are redirected to unique URLs (indexA.html vs. indexB.html vs. indexC.html, for example). This behavior was contrary to my initial assumption that all visitors got the same URL, as is the case for GWO multivariate tests. Since URLs are unique in an A/B test, you can simply view the pages report within your Web analytics tool and filter on (for example) index*.html to see one row per variation.
Do I need to pass any custom variables from GWO to my Web analytics tool?
No. You don’t need to pass any custom variables to get reporting for an A/B test.
If you're running a multivariate test, on the other hand, you must pass the GWO variation ID to your Web analytics tool as a custom variable, since the URL remains the same for all variations. If you’re interested in this technique, there are good discussion threads on this topic in the GWO support forum.
If I optimize for bounce rate outside of GWO, do I still need to set up a goal within GWO?
Yes, but it can be a simple placeholder. When you create a GWO A/B test you’re required to provide a conversion goal before you can launch. However, if you're planning to optimize for bounce rate or some other metric in your standard Web analytics tool, you can spoof a GWO conversion goal by specifying a dummy page somewhere on your site. In effect, you're simply using GWO to manage the serving of page variations.
To prove that it can be done, here are some screen shots from a test I set up: