Just as idea , you can use the info you have about the server on gametracker and try to analyse it .... you can see there how many people is connected on the server , when ( what map ) the server have more people , in what map the people use to left .... that kind of things in my opinion are the best indicators of what is fine and what is bad .
Is not possible do magic to fill servers but you can use the stadistics of the server to try to improve it .
I have tried to do on bf2 servers but nobody hear me ...lol
nice idea men im gonna take care it lol