That feeling is really awesome. I have got two merits so far and I was really delighted to get them. I will always remember that moment and the post that got me those merits. It was the time when merit system was introduced and a lot of people used to post doubts about the merit system. I first learned about the changes and then started to make replies to their queries. I knew that sooner or later a senior member will see it and reward me. These days I am not that much active but I plan to post more often in meta section.
I think it encourages newer users to be more friendly and helpful towards new users and even if it's in order to gain merit then it's a worthwhile causen to increase the friendliness of the forums in my opinion. Also after receiving 10 merit myself I can't really complain about the system anymore. Already given away my smerit though, don't like the idea of keeping hold of it personally.
My only criticism is that there are some members with a lot and receiving more, but don't give any merit out. It's not like it's costing them anything either to reward others

A reduction in merit if you squat smerit would be my proposal, say after 3 months of not giving out or any or something. The idea of sitting on it is presumably in the hope of the "value" of it increasing due lack of supply, whereas supply should be regulated by those who distribute, not by those who are holding smerit for no benefit but themselves.
need to merit for bounty
This is how you don't get merit.