It is quite difficult to find meritable posts, especially if you don't have time to visit all the boards. If one finds a member who hasbeen a consistent and productive member of the forum, then it is easier to award merits as a block in a single post. It can make it difficult for newer members to understand that the merits have been awarded to the poster, rather than the specific post.
As has been stated many times, itis better to focus on the benefits derived from being an active member of the forum, and not to chase merits just to gain rank.