As per the forum rules[1] :
Q: How does activity work?
A:
Quote from: theymos on June 18, 2013, 08:44:42 PM
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 hour.
For example, if in a 14 day period you post 14 posts, you gain +14 activity.
If you post 2 posts in a 14 day period, you gain +2 activity.
If you don't post at all in a 14 day period, you don't gain activity.
However, if you post 15 or more posts in a 14 day period, you still gain only +14 activity.
In short, you are only able to gain 14 points in the activity section of your profile in a two-week period. You may post more within that two-week period but your activity will reach a threshold (until the two-week period is reached). You can see even more information about activity on the following thread :
https://bitcointalk.org/index.php?topic=2766177.0
[1]
https://bitcointalk.org/index.php?topic=703657.0
