This process is not unique to wikis. CentringArtifacts are a quite powerful tool to organize loosely connected people through IncidentalCollaboration.
When the primary CommonContext connecting the participants is their need for and enjoyment of the CentringArtifact, there is a collective desire to see the quality of the artifact improve over time because it benefits everyone. Furthermore, as PersonalRelationships between CommunityMembers depend on the fidelity and effectiveness of the CommunicationChannel over which the relationships are enacted, there is a pressing need to develop BehavioralNorms that guide efforts towards a higher SignalToNoiseRatio. The pressure to normalize is not subtle. As noise increases--through trolling, vandalism, or a flood of newcomers unfamiliar with the norms--MaintainingRelationship?s over the medium becomes increasingly untenable. The risk of losing hard won friendships motivates the community to fight to OrderChaos.
The higher the quality of the artifact and the more socially ordered the space, the more attractive the artifact becomes to AdoringFans as well as AttentionSeekers. At some point, the on rush of newcomers may exceed the desire or abilities of the community to maintain order. Thus, while initially quality creates a VirtuousCycle?, it is not a stable cycle.
The cycles differ greatly between those primarily motivated by MaintainingRelationship?s and those primarily motivated by their need for the artifact as a resource. The sentimental group will value their relationships over the utility of the artifact, and thus they may let it degrade. They are more likely to form cliques to empower themselves politically, and are likely to wander OffTopic into InsideJoke?s an tangents and justify it by saying OnTopic is by definition whatever the "community" wants, when they are really only speaking about their faction. The other side of the equation are functionalists. They are much less likely to form a nameable political identity, but because of their common SuperordinateGoal of maintaining a resource useful to all members, they can quickly come to agreement when their common interests are threatened.
Ultimately, a community is much more likely to succeed into the long term by keeping focused on artifact itself rather than its secondary benefit of being a "centre" around which PersonalRelationships can easily form. After all, the higher purpose is what attracts interesting, valuable outsiders to join and contribute. Without new, interesting, valuable people constantly joining, the attrition as community members leave will either lead to a GhostTown or to allowing less than valuable people (usually trolls) to take up space inside the community.
I have serious writer's block. Sometimes the best way is to just start writing and pile on, so forgive the brevity of this. -- SunirShah