You don't necissarily need to be active in this thread but in all threads that fall under the 'Alternative Cryptocurrencies' department of this forum (
https://bitcointalk.org/index.php#6).
A Jr Member gets 0.5 stakes. So being active gives you a double reward because it helps you to get promoted (and earn more stakes for the same activity).
Stakes is a widely used system on this forum. For CREDITS 2% of tokens are given to the bounty program. Of that 2% 30% is used for signature campaigns. The participants get stakes for their activities. These can be understood as shares. The more stakes you collect in comparison with your collegue signature bounty hunters the higher percentage of the before mentioned 30% signature tokens you will get.