Some types of communities are very obviously closed to a selected audience alone and others tend to be fairly open or public based on several criteria. I have often been asked about what the criteria would be to determine when a community would be private versus public. Here are a few categories that we have consistently leveraged:

1. Valuing quality over quantity: There are several reasons why you want the sample size of your community to be large enough and representative enough for you to make decisions regarding future direction. In most cases we have found that due to several reasons, more opinions are not necessarily different opinions. More of the same skews your percentages, but you might infer the wrong things based on the outcome of a community agenda. When you value getting enough of the right data instead of as much data as possible go for a private community.

2. Resource availability: More community members equals more resource requirements (staff, hardware, software, etc.). There is no simple way to get over this fact. If you have a pilot project to test out with a limited objective or specific outcome within a defined time, go for a private community. If resources can be appropriately accounted for public (accept all communities give you more leverage)

3. Growth into adjascent markets: If you can plan an account for a social network to GROW into new markets for your products and services (adjascent spaces) by building a community and migrating their needs to new products, then go for a public community.

4. Brand alignment: Many companies we have spoken to have a strong need for “controlling and managing” their brand. If so, a public community provides fewer options for this: since you risk being looked at as a police state. If your brand definition and acceptance has ability or the risk profile to morphe over time choose public communities.

5. Monetizing metrics: Most independent communities are primarily monetized by ads – keywords and sponsored. The more the traffic, the more the chances of ad revenue. Public communities enable you to reach larger audiences. On the flip side a private focused community usually gets greater CPM since the audiences is filtered and culled.