Credits.
Making a network post: +10 credits
Posting an open log: +15 credits
Creating a new alliance with someone (i.e. making new CR): +25 credits
Each string over 10 comments: +5 credits
Each string over 50 comments: +5 credits
Each string over 100 comments: +5 credits
Replying to another character's post or thread: +5 credits

( Arena 07 Tracking )