If you agree with a poster, but don't have much to add to the point he has made, do you think it is good practice to award merits without quoting and posting an agreement?
I wouldn't do it for posts you "agree with", but for posts that are worth reading. I've done this to posts that stated what I wanted to add to the thread already, so posting it again would be spammy. So I try to highlight the post by Meriting it.
I guess it's caused by actually reading the thread, instead of just responding to the title or OP. I'd say that's a good thing.