Community of purpose
A community of purpose is a community of people who are going through the same process or are trying to achieve a similar objective. Such communities serve a functional purpose, smoothing the path of the member for a limited period surrounding a given activity. For example, researching a topic on Wikipedia.org, buying a car on autobytel.com, antique collectors on icollector.com or individual investors on fool.com. Members of the community assist each other by sharing experiences, suggesting strategies and exchanging information on the process in hand.
Communities of purpose enable and empower people accomplish things. The community's purpose revolves around allowing people to accomplish something they want or need to do, whether it's buying, selling, fixing something, or dating. The design and implementation of a community of purpose depends on the intended outcomes the site serves. The aspect of community that empowers a community of purpose has to do with the ways in which the people who participate, assist, and inform others along the path from having an un-satiated want to achieving their goals, objectives, and tasks.
From user-generated reviews or collaborative filtering on a site such as Amazon.com which help people decide what to buy to the reputation system at eBay which gives users a sense of who they're dealing with before they transact, the community fuels accomplishment. The gravity of the given community of purpose is directly proportional to how much it makes possible for the people who are there to get something done. While the size of the community matters it has a lot more to do with how effective the participants in the community are, in fact. However, the size and scale of the active community participation are important as it relates to fulfilling the needs of those who around and are willing to engage to get what they want. Effective communities of practice are balancing act between offering the right capabilities and ensuring sufficient capacity to deliver efficiently. With the possible exception of electronic commerce, media consumption, search, and research (as in Wikipedia) communities of purpose are the most underdeveloped properties on the Internet.