What I see from the research perspective, Bitcoin and other Cryptocurrencies are more popular in developing countries. It is because people are more inclined to participate in the bubbles due to low financial literacy (nothing bad about bitcoin but the majority of people came in the highly speculative market conditions) or because they simply don't have access to the stock market. Despite lower interest from the developed economies, more money flows into the digital assets from this countries simply because of they are wealthy, e.g. it is estimated that US bring 40% of ICO investments (as of Q2 2018)