I'm taking a course in GIS and remote sensing, and last week's module was about visual image analysis - you know, the methodical way you take an aerial image apart to figure out what you are looking at. I shared the Geoguessr page with the class and it has been very popular. Most of us reported coming up with a fairly methodical way of analyzing each scene to figure out where it might be.
BTW, the best I have done is about 18,000. So addicting...