As with all the web tools that I sell, I have been actively using HeatMap Magic myself for almost a year, and on the sites of my consulting clients for almost that long.
My websites are the foundation of my reputation and success. I am always wanting to learn as much as I can about how to improve the experience when someone visits one of my websites. My clients are actively engaged with their Google Analytics accounts, but there are always questions about the behavior of their visitors while on their site.
I provide HeatMap Magic to them as part of my services, and the insights that are gained help them make informed decisions and changes to their WordPress sites without the guesswork of the past.
There is power in the knowledge of exactly what your visitors are doing on your site and their interactions, far beyond what can be gleaned by Google Analytics alone.