When you send a Google Earth tour to a very naive -- even phobic -- user, you pretty much have to tell them exactly what to do to get a satisfactory tour.
To see what I'm talking about, do the following. Download Google's sample, from https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCEQFjAA&url=https%3A%2F%2Fdevelopers.google.com%2Fkml%2Fdocumentation%2Fkmlfiles%2Fballoonvisibility_tourexample.kml&ei=uLviVMu8DuLAmwXGvYGQCQ&usg=AFQjCNFw11Z9TSZNIh3ARQsZCVLTQRbk2g&sig2=cW7QOZ7sgsz9PIVOMvNPGQ&bvm=bv.85970519,d.dGY .
Click on the kml file and Google Earth will start. In the left panel, you will see the "balloonVisibility Example", and the "play tour" button looks like a folder.
Click the "play tour" button. The tour will play, but only according to parameters set at menu Tools>Options>Touring, not according to the kml. That's a problem: most naive users don't even know Tools>Options>Touring exists, and it defaults to "show balloon when waiting at features" un-checked. The result: no balloons become visible.
Now un-check the "Play me" box (fourth and last item below "balloonVisibility Example"). The "play tour" button changes to look like a video camera. click it, and the tour plays as as declared in the kml. This is an un-intuitive way for a naive user to have to run a tour; his intuition is to simply click the folder icon in the first paragraph.
Is there a simpler way?