That poses an interesting question: what is the optimal size of an online community? My first guess is that it would have to be significantly different than 150, since of course no one lives permanently in an online community (except, perhaps, for the more obsessive WOW players). The true number might be larger or smaller than 150, depending on how you interpret the impact of that asynchronicity. The repeat visitor figures on the sites I currently work with indicate that the average community member -- defined as someone who comes back to the site repeatedly -- probably doesn't visit more than a couple times a week. My own experience -- being a borderline obsessive-compulsive -- is that I would visit a community I actively identified with five, maybe six times a week. So let's assume a range, where there are a few core users who come by almost daily, and a much larger number of people who visit once or twice a week. What in that dynamic might allow us to identify an online community's tipping point?
I don't have answers. I'm not even sure there are answers to be had. But there do seem to be some interesting avenues of investigation:
- The Tipping Point tells us that the importance of community size is communication and shared experience. So, in online terms, you can ask how many pages of copy -- articles, forum posts, what have you -- a reader must take in to arrive at a shared experience with the other members of the site, and then you can estimate how long it would take to read that and compare that to the amount of time visitors are actually spending on the site.
- Clearly a community can be both too big and too small. If we're talking about forums, for instance, too few users give the impression of a wasteland; there's not enough getting posted to reward the visitor for coming to the site. Too many community members, though, and you have a blizzard of posts that no one could possibly be expected to read in their spare time, and (as in the communities cited in the book) you'll see you community fracture into two or more. Now, you might not care -- if all you boss cares about is page impressions, a fractured community is as good or better than a unified one -- but it's worth wondering whether the cohesiveness of an online community can contribute to its long-term health.
- There is one feature of online communities (well, more than one, but bear with me) that sharply distinguishes it from offline communities, and that's the fact that upwards of 90% of its members are casual, part-time participants. Online communities are more like a big-city bus terminal than they are like a city, or even a company; they're full of many people hurrying by on their way to something else. What impact does this style of drive-by community participation have on the community experience? There certainly must be a degree of alienation that results, but how to quantify it?
More work is required. It's a potentially crucial question, though. Community is formed when people come together, and common sense tells us that too many people and too few are both bad. So somewhere in between is the sweet spot, the ideal number when things just click. That number exists. But how do we find it?