Well, i think i get it but still have one doubt!
Merit can only be send right?
I mean they're no system (if your activity reach 100 or 1000 plus you'll Automatically receive merit)
Note: To be honest (before i found this Forum) the hole time i thought i'll Automatically receive merit if my activity goes higher.
Yes, what the user @DdmrDdmr said is very relevant

Well, just to reiterate
Merit = you can get
sMerit = you can send
For every 2 merits received, you receive 1 sMerit.
This type of process was implemented on the forum, because the users do not cheat exchanging merits/smerits each others
Another detail I would like to share is, in this forum, there are merit source users, they are one of the main influencing factors of merits here on the forum, as they distribute newly minted merits.
In this topic, @theymos explains how you can become a merit source

If you want to be a merit source:
1. Be a somewhat established member.
2. Collect TEN posts written in the last couple of months by other people that have not received nearly enough merit for how good they are, and post quotes for them all in a new Meta thread. The point of this is to demonstrate your ability to give out merit usefully.
3. We will take a look at your history and maybe make you a source.
I am especially eager to have merit sources in sub-communities such as the local sections.