If not the above energy boosters in the forum, many users would have used their energy in another profitable platforms or using here as a chatroom. Is there any other energy or immune booster?
I don't agree with you in this very one because I've seen alot of active accounts who have been on the forum for over years and still at very low ranks without any signature campaign or so.
I agree with you in the basis of merit as a morale booster as you named it because for every merit I receive, there is always a huge joy in my heart certifying that I'm doing a good job.
Truth be told that merit is a prove that your post captured a heart and possibly solved a problem or gave solution and everytime I earn one or more, I feel fulfilment.
On the basis of investment, I would say that having a profitable investment somewhere that give hopes of money is also a major factors enhances once stay in the forum as investors wants to stay ahead of the market and with an active presence here, there are chances of staying ahead of the market if the right things and analysis are Ben done.