I do not know exactly, but I guess the most appropriate countries in as Japan, Spain, china and Usa, Maybe I can add hong kong and singapur to this list. I thought to meet the needs of the tourists in the regions where tourism is concentrated.
I knew that Chinese and Japanese are the best country do in trading platform. Chinese have own the many bitcoin related since japan is made bitcoin as a legal money. If china make bitcoin as a legal in their then the will become control over ahead the US government. I hope my country also will do the same.