Lika your start. It seems from your suggested KPIs that they cover many different situations och online environments.
- The membership measuerement is valid for formal memberships lika MySpace, groups in Facebook, Ning etc.
- Newsletter and subscribers are more focused on web sites, than for instance Facebook groups?
- Active versurs passive behaviors are very different depending on situation, do you think the same KPI could be used on forums, online social networks, websites, blogs, and also mirco blogs?