I have read so much thread asking on how could they earn from this forum, actually there is no wrong on asking about that, let us not be hypocrite we are all here to earn money and to gain knowledge.
Good for you that you also said "to gain knowledge" because I'm about to contradict you already 
. But you know what? How sad that there are really existing members (especially the new created accounts) that just came here solely because of money. Right after they heard about sig campaigns and bounties, they suddenly jump here without knowing that it's not so simple. Tendency, they spam everywhere but I'm glad that such cases are now minimial due to Merit system. With this only the people with pure intentions will remain 
. This forum is applicable for gaining that both, that is what I like the most in this forum, Our earnings in this forum will come if we get old here, just focus on creating useful posts and creating information that will help people who will read your posts.
Just a reminder, don't stressed out yourself on earning merits. Just enjoy and do your part as a responsible member here and good karma will follow .