Interesting research, BDSAIME. I know that you have acknowledged some weaknesses and the numbers might hold up, but dominaguide.net seems to be woefully out of date. In Georgia it has 8 listed (only 2 of those still practice but that is not the point - but it does tell me that the numbers might not reflect today's reality). Conversely, on Eros Guide 13 are currently advertising and I know of a handful of others that practice but don't advertise there. I would put the actual number to be somewhere around 18, not 8. The same goes for Washington, DC. Dominaguide shows 6 while there are currently 22 advertising on Eros. A couple are visiting but again I know of several that don't regularly advertise so I would stick with 22-25 opposed to the listed 6 on dominaguide.net.

If all countries are under reported on your source then the numbers hold but I am thinking that the US is coming out a bit lower in the ranking than is reality.

Finding a more accurate source than dominaguide.net probably wouldn't be worth the effort, so thanks for putting the work into this and getting us thinking about it. Switzerland was certainly a surprise. I just don't see them being that much kinkier than their German neighbors, but who knows . . .