big NOTE: AFTER MOST BUGS ARE FIXED....
You could make 2 private servers.
1. Being the same as it is now... for the people who have time to play the game.
2. A High EXP/DROP etc (for fun server) which people who have a life and not much time can enjoy as well.
I can almost guarantee it from private server's history that the HIGH EXP/DROP stuff will generate more income if you base the cash shop/what ever in a good way.
Say for example for Dogis, something not needed but cool to have.