If the primary focus is (mandated) content choice and the goals are attraction and retention, then insertion destination, interaction, and frequency are primary steps. As well, working under the premise that a community has been developed and is capable of the interactions you are seeking, then a primary goal is to let as many people who know you have the content, know. Process: (target or potential target) details about the destination community.
We begin discussion with this outline in mind:
b. choice(s) (target)
c. frequency (destination) (schedule of posts and type)
d. capability (enabling of community to act on their own)