I've been playing this game for about a year, it was originally planned as a backup option, but now it's become the main one because the income is very even here, 30% is stable, it doesn't fall below. I work with tier 2 countries, mainly the CIS, but I don't want to go to Tier 1 because there is a lot of competition there. In my experience, the CIS is the most balanced region in terms of income/investments. I receive payments in the crypt, so they come very quickly.