Obviously a microsite is going to need more than just a forum, but I imagine that for a successful microsite the forum would be the most important part of it. To test out the system I created two forums around two bands whose products I sell, Maruru forum and Antic-cafe forum.
Deciding scope
The reason for starting several small forums instead of one big one is to create a sense of belonging / identity for those using them. People seem to feel stronger attach ment to smaller circles. For example people will feel a connection to those attending the same school as them, at a lesser level to those living in the same city as them, even lesser to those from the same country. I want to find the optimal "circle size" to get people to feel that attachment, while not limiting fruitful conversations that could have happened if those circles were combined.
For example I could have created a "japanese music" forum instead of having "maruru" and "antic-cafe" as separate forums. Perhaps I should have, not sure, still experimenting. Certainly someone who is an enthusiastic fan of Antic Cafe would feel less at home at a generic forum for all Japanese music. Still there clearly has to be some minimum size at which an active forum is still possible, if there wasn't I could create a forum for people from Vatican who like Michael Jackson and are into cross-dressing. It would be a small group, but man would they be into it.