I love Google Earth and use it regularly. Today, for the first time, when I clicked one of the icons that popup information about or photographs of a particular location, there were "Sponsored Links" in the popup! Poorly targeted, yes, but they looked like a new AdWords location to me.
It [poorly targetted Google Earth sponsored links] sounds like another case of the targetting being affected by the ability (or lack thereof) of the AdWords advertisers to select the appropriate tartgetting fortheir campaigns.
However, if advertisers use the targetting features badly, it can result in poorly targeted ads appearing in Google Earth - e.g. An Ad if specific to London is targetted at the whole of the UK, it could appear as a poorly targetted Ad when looking at, say, Manchester.