Currently, there is only 1 title attainable when you reach the 10,000 post mark called "Flyertalk Evangelist". If reaching the status of "Flyertalk Evangelist" is equivalent of Platinum status, why not also give away Gold and Silver?
Here is what I propose:
For 5000 posts, you can attain the status of "Flyertalk Elite"

For 2000 posts, you can attain the status of "Flyertalk Novice"

Now, it doesn't exactly have to follow my titles, however I think giving members attainable status is a good promo.