Having said that, I'd actually not call merit source duties as their/a job, I think it's much better to say it's their own contributions to the forum. 
A community initiative that some applied for while others were selected for it based on theymos' own criteria and selection methods. I had out merits in a similar way as The Pharmacist does it. I just go about my business of reading and writing posts and I merit the good ones I find in the threads and sub-boards I regularly visit. That's the simplest way to do it. So far I have always succeeded in emptying my bags at the end of the month.For each member of this forum, who is also a merit source, the situation is different.
When I applied in Meta for merit source I did so with the motivation to help my local community on the forum, as many of them were new and young members and mostly wrote in the Croatian section of the forum.
I also explained this in my merit source application in Meta.
I believe theymos recognized the need to add a merit source that understands the local language and can reward with merit quality and good local posts, and I also got a lot of support from the local community.
From this it is clear that I think I have an obligation to pay more attention to local posts in the Croatian section of the forum, but I will also always reward quality posts in the English part of the forum.