It's my understanding that there are people who get Smerit to start with, then they give merit to posts they like with valuable information. From there, the person who received the merit will also receive Smerit to spread the love. It's like internet AIDs and we're trying to be infected.
Yes Merit and SMerit two things are there , When someone send a Merit to someone else , it is actually 0.5 Merit and 0.5 Smerit.
So to reach 1+ Merit a person need to get 2 times Merit to get 1 Merit + 1 SMerit in account to give to another person.
This is what i understand so far.