Screenshots
To illustrate how useful Google Earth can be during the buying process, let's imagine for a moment that you're interested in buying Lot 27...
In this screenshot the lot plan (transparent white) is overlaid on Google Earth's imagery (backround), making it possible for you to pinpoint the location of Lot 27 and
inspect its surroundings.
Zooming in to Lot 27 you can determine its elevation by placing the mouse pointer (white hand) over the property. (Needless to say, higher places mean less susceptibility to flooding.)
Rotating and tilting the map to simulate a bird's eye view of the site, you observe that the terrain is slightly sloping toward west (you know this because of the compass). You also learn that there are mountains up north.
Clearly, Google Earth tells you volumes about the project without you having to actually visit the site.