Re: Your post history is responsible for your unmerited status.
You need to look at some posters' history to see if the post is out of character. If it is, then it could indicate a purchased or stolen account, or possible plagiarism.
Sometimes if I visit someone's post history just to do a little background check I will notice that he only has just one good post (the one I am considering sending a merit) and the rest of it is trash, that is when I realized the chances of it being a copy-pasted post is high. The bottom line is doing background checks won't hurt as your sMerits are really limited and you must send it to people who are really deserving.
Was never thinking about plagiarism. Because I wasn't thinking too much.
When I first registered I was only just lurking here, reading a bit, learning and never had any intention of writing until I joined one sig. campaign. Even after that I think I was never spamming, I was always trying to post something relevant, engaging in some discussion or so. But to be honest, although it wasn't a garbage, it was not worthy of a merit.
Only after some time I gained courage and tried to earn some merit.
Because of that, because of my situation I was always thinking that others were in similar situation so that it would be really nice to reward someone who decided to upgrade his posting. (So in my mind, there was no need to check one's history because it's ok if s/he was not such good poster before, it's ok if he's almost always posting something important.)
OK, from now on, will open one's history and even report if needed.