It has nothing to do with postcount (ex: Marcathonas is second only to me but is still a Citizen), only the quality of your contributions to the community (genuinely helping people with questions/problems, not spamming or flaming needlessly, etc). Unlike some people seem to believe, you *do* need to actually be helpful and not just post things that boil down to "I want to help, but I have no clue"...
Ranks are given out by Stardock whenever we feel like it, if we see people who we feel deserve recognition for their efforts. But regardless of any efforts you make, only a few instances of you acting up can be a quick way to have Brad veto your promotion