When new members sign up here at the site, there's a field where they can put down a member name of some existing member who made them want to join the site. It doesn't necessarily have to result from an active "Hey, go join the site" recommendation from an existing member. It can just be a situation where a long-time lurker finally decides to join and puts down Skink's name, for instance, because he'd been reading and following Skink's posts and thought he was a good guy who helped the new member make up his mind to join the site. Hope that was a semi-understandable explanation.