For anyone not familiar with the topic:
Star Trek Online's Duty Officer system allows the player to accumulate a roster of NPCs (Duty Officers) and assign them to a variety of missions that are carried out in the background, whether or not the player is on-line - the missions simply run out a real-time clock (a few hours to a few days) and then randomly determine an outcome. Outcomes consist of minor awards, such as crafting ingredients or temporary power boosts. Missions require suitable duty officer NPC's, some money and sometimes additional items. Duty Officers can also be traded between players on the open market. They never appear in-game - they only exist 'on paper'.
I have fun with this system - it feels like a combination of trading cards and a simple strategy mini-game. It always gave me something to look forward to every time I signed on - "What did I win this time?" It was a handy way to chase after that elusive chunk of unobtainium for some must-have gadget.
What villain wouldn't want a rogue's gallery of henchmen to dispatch on menial tasks as part of his Master Plan?
What hero doesn't have a fan club of eager volunteers somewhere, just waiting for the chance to help out?