When you join GGx, you automatically become a member.
If you have posted 100 post, you are promoted to a GGx member addict, and you will have access to more features and priveledges. Posting 300 will earn you a place on the GGx staff team, and 600 will get you a sure spot on the global moderation team. Anyone with 1000 post or over will be promoted to the Administration team.

0-100 post-Member
100 post-GGx member addict
300 post-GGx Staff
600 post-Global Mod
1000 post-Administrator

If you want to earn positions the easy way, you can also enter competetions and post suggestions that will help you become more respected members faster. Minor comps will earn about 5-10 post, the higher grade comps can earn you as much as 50 post, but this will be in the near future.