Military ranks are no bad but stretch them out over say 2000 posts. Also give some instant gratification. If someone makes, say 10-15 posts, bump them up from private to pfc. If someone sticks around that long they will probably stay. Put a rank icon for each level.
One more suggestion, Please don't make me go from a senior NCO to Butterbar. It just isn't right. Make the jump to at least to 1st Lt or Lt. JG depending on the service you choose.
If a bunch of people start making General You could break them down into Brigader General (1 star), Major General (2 stars), LT. General (3 stars0, Keep General (4 stars) for yourself.
Be sure you can issue "battlefield promotions" for meritorious service. Some people always shine. Thinking of people like Dave on the old M-1 Board that was an expert on stock repair and shared his knowledge.
I like Firemedics idea. A little rank icon next to your user name. Only prob would be choosing a branch of service. I'd draw it out a bit though, 100 posts and/or replies or so. Makes it something to go for , you know. FUN! And it might keep the activity stepped up.
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