Upon having a short googling I found out that the most country that commonly used cryptocurrency is Nigeria, how this will come as I heard they banned any merchants or exchanges that associated with cryptocurrencies especially Bitcoin. But why not in Switzerland? 
If I am not mistaken, Nigeria is the country with the biggest population in Africa - 210,178,123 according to wordometer. Switzerland just has 8,703,198 peopleAlso, MLMs, Ponzi and pyramid schemes seem to be so rife in Nigeria and most probably need members to make and receive payments in cryptocurrecies.