Mining enterprise:Full member?

Im a bit confused about building mining corps. When I try to build them it says I need to be a "full member". What does that mean? Im already a member of this game. My country has crazy stacks of oil and I would love to become a country that is dependent on oil.

It probably means that you need to pay for the game. It's $6 for 1 month or $12 or 3 months.