On Friday the Google Blog offered a peak into some of the studies they are doing around their user interface.
This picture comes from an eye-tracking study that Google conducted. The deeper the color, the more a person's eyes focus on that part of the page.
Based on this image, all the focus is on the top two results. Coming up fifth or sixth on Google doesn't seem to garner much attention. It really pays to be number one or two.
As a side note, it's interesting to see that Google is constantly studying and testing their user interface. Too often a website is built and the interface is left alone for 2-3 years with no testing, tweaking, or continuous improvment.