building communities

It seems to me that one of the principal effects of the internet is the creation of communities. Communities are built around mailing lists, chat rooms, web pages, and blogs. The effects of these communities are only starting to be realized, since many people have yet to take full advantage of the internet and the technologies exist to make participating in communities possible. And new technologies are still being built that promise to make building communities easier as well as make them more valuable to their users. At the same time, the way to make money from these communities is still mostly unknown.

How to leverage the knowledge that online communities will become more and more relevant in the near future is the key question. Early signs of the value of the blogosphere have started to show, as popular blogs are able to sell advertising. Some blogs have been sold to companies altogether, whether for their content, or merely for the value of their audience, I'm not totally sure. My guess is that the value seen is mostly based on the audience, both for their numbers and for who they are. Communities are based around shared interests, so a popular blog represents to an advertiser a ready-made market niche.

For subject areas where a multitude of voices is valuable, the number of communities will be relatively small, and the size of those communities quite large. One can look at the most popular blogs and see that once they become popular, they tend to stay popular. Of course it is important for the content to be there, but when the content is provided mostly by the audience, it is obvious why blogs are self-sustaining.

So in the future, the internet will be built by community builders. What are the communities not yet mapped out?