You have to pay for the community utilities, door people, elevators, exterior maintenance/repair, roof repair, and snow maintenance that people won't pay for as a group when given a chance. It's really the only lever that guarantees compliance the least amount of drama. The alternative is that you have to file civil suit to settle obligations. (You share a roof with your neighbors.. they refuse to pay for it because the roof isn't explicitly over them, they refuse to shovel and everyone gets fined.. etc)