Generally, people who want to join the exclusive Hedgehog community as a Member must be invited by someone who is already on the site. (From time to time we open Member status to all new accounts as way to share the platform and help more people join the community.)
Invitations are still a big part of Member status, though – if you’re invited, that links you to the person who invited you, and you benefit from each other’s Respect and invite trees.