Yes, it's shows your place in this social group and how good you are at posting critics.
Each review you make will give you 1 custom reputation.
Each award will give you custom and some real reputation.
Idea is to keep you motivated and commended for your work.
Also after 2 or 3 months when there will be many of you with like 30-40-50 reputation, users will start to recognize you, they will start asking you for posting reviews on their maps. True this is a little hard for starters, but they can always work out they way to the top. And when the time comes for new moderator to be selected, users with high custom reputation will be first to check.