A computer hosts an online community for a business entity. The community includes multiple feedback interfaces that quantify each user's engagement with the community. Each feedback interface has a distinct interaction time scale, from immediate to a year or more, with intermediate feedback interfaces. The process measures reduction in technical support costs based on the community engagement, and alerts a community manager when too many users are not completing a task for one feedback interface. The manager creates a targeted mission for the appropriate subpopulation of users. The mission specifies an action and a time limit. Completion of the action increases completion of the task. Messages are sent to users in the subpopulation to alert them of the mission. The mission feedback interface provides feedback visually for users in the subpopulation. The mission feedback includes indicators of remaining time and percent completion.