You need 30 in activity, you are close now

The activity number is determined in this way:
time = number of two-week periods in which you've posted since your registration
activity = min(time * 14, posts)

Activity is updated every 30 minutes.

Read this link: https://bitcointalk.org/index.php?topic=178608.0
On the link above you can read all about rankings/badges.

Let me know i can assist you further