[andrewwee]

I've seen that recently, i think it's on one of google's helpfiles.
It just shows the golden triangle being the top 3 organic search results and the secondary hot zone are the other results on page 1 of the SERPs.

If you want some cool heatmap analytics, you can check out neil patel and cameron olthius' free heatmaps at crazyegg.com.

As with all analytics codes, I'd place it at the bottom of your pages, so that it's processed last and your visitors won't see a white screen for 5-10 seconds.