As the new promotions officer, I have noticed a countless number of people who were promoted without an introduction about themselves. You have one week to write an intro in the forums or you'll be demoted back to Private rank.
There are also a number of recruits who are due for a promotion, but have yet to write an introduction. Until you get that done, your rank will stay the same.
Be sure to look at your profile to see if your age/location is listed. If you have "Earth" as your location, it will need to be changed. A picture is required as well. The one that is given to you does NOT qualify.