Coindesk, which covers the news and prices on digital currencies, recently came up with this top 10 list: 1) Argentina 2) Venezuela 3) Zimbabwe 4) India 5) Nigeria 6) Brazil 7) U.S. 8) Nicaragua 9) Russia 10) Iceland The ranking is based on 39 variables. Among the categories examined to determine the ranking: technology penetration, inflation, history of financial crises and the size of a nation's black market.

http://www.bloomberg.com/news/2014-09-25/which-countries-will-buy-into-bitcoin-.html