Four types of exclusivity of brand communities

There are four types of exclusivity of brand communities, which are as follows:

1.Open - These are communities that do not require registration in order to participate. Examples of these include message boards that allow anonymous posting and blogs that do not require registration in order to comment. Facebook Pages and other similar social network groups can be included in this category.

2.Registration - These are by far the most common form of brand communities and require nothing from the user but registration.

3.Purchase - These are communities that require either the purchase of a product or a membership in order to join in addition to registration.

4.Outside Selection - These are communities where members cannot self-select themselves into the community. They must be selected to join by the organizer of the community or invited by an existing member.

The eBay community falls under the category of registration.
Can you name some other communities for these 4 categories ?