I would like to suggest a new medal, the Map master Medal.
For each map that exists, a Map Master Medal will be given out to the individual who has achieved the most unique wins on that particular map, on the condition that said individual has also played that map a minimum of X (100 or even more?) times.
This will cause the medal hunters to look for maps that might be relatively unplayed and start mass playing them which would increase the traffic on the site.
Anyway, these are my early thoughts which are still developing because for certain popular maps the Master might switch a lot...