First person a new visitor will meet and know (Have paper and pen ready to copy names).
Represents the church (look, dress, act as an ambassador) ... if they return.
Source of information. i.e., bathroom, classes, nursery, church info.
Facilitator for a challenging situation (visiting a new church where you know only a few or no people at all). Reassure visitor that all will be ok.
Networker. Start embedding them into congregation by introducing them to elders, ministers, their children's teacher, other members. (Greeters, don't just talk to each other)
Usher. Direct or facilitate finding them a class or a place to sit in the auditorium. Invite them to sit with you.
Contact. Greeters will have cards with pictures and contact info in case visitors have follow-up questions or simply to help visitors remember who greeted them. Phone or email will be the church's where they can leave a call back number.