Use one Site Collection or multiple Site Collections?

Some important concepts:

  • a site collection is a unit of information belonging together; if information should be isolated/secured, it could be a separate site collection;
  • having multiple site collections might require some additional development (e.g. packaging content types or site columns that you want to reuse in different site collections in features);
  • a lot of built-in web parts only work inside a site collection, not across site collections;
  • it’s good to have separate site collections for a corporate, governed intranet and the wild wild west of collaboration 🙂