Forum Moderators: rogerd
Can anyone give me an idea of what that work might be? Is it things like weeding out spammers, etc. that takes so much time?
If your forum gets really busy, the admin load will increase - dealing with member problems, managing topics and pruning/archiving, managing mods, etc.
Dealing with trolls, obnoxious members, and spammers will take more time as the forum gains popularity, though eventually your mods can carry a good part of that burden.
A forum is a lot like a garden - it needs a lot of loving care, although the kind of care needed changes with time. People can tell when they are at a good, well-managed forum and are more likely to stick around.