Bryan Eisenberg posted a brilliant example of how eye-tracking analytics (mentioned in our recent article 11 Types of Analytics for 2011) can help you out with "the why" by showing you what your visitor "sees" in your design, which suggests why certain calls to action, for example, aren't clicked.
The example is Land's End's calls to action in a pop-up box that appears after an item is added to cart. You know the type, a window that asks if you want to continue shopping or proceed to checkout, a method that is used by countless online retailers.
Eye-tracking tool Feng-GUI reveals that attention is focused anywhere but the calls to action!
It's a bit blurry in the screenshot, but the calls to action are stacked (groan), and given equal "weight" (size, color and prominence). The top button says "keep shopping," the bottom "shopping bag." The product page's content and cross-sells compete with the calls to action, and they appear to get no action from eyeballs.
Check out how a smart redesign fades out the background, fixes the button styling and changes the "shopping bag" label to "view shopping bag" (more clarity).
The impact on attention is remarkable:
Attention is focused on the product image and call to action. Observe that the more prominent call to action receives the most eye-fixation love. In this case, the "keep shopping" button. Land's End may wish to test switching the order to see if making "view shopping bag" more prominent results in more absolute conversion.
The point is, eye-tracking tools can be very helpful in designing A/B tests or redesigns because they show you where on the page a potential design problem is, rather than just showing you quantitative metrics. You need both qualitative and quantitative data to make great testing hypotheses. Web analytics used in conjunction with eye-tracking (or other qualitative analytics tools mentioned in 11 Types of Analytics for 2011) help you get the most out of your web optimization program.