Abstract: A system for building a database that stores information representative of the organizational structure of a community of users of a computer network is disclosed. The system uses an online computer applications service that facilitates the initiation and completion of transactions between users in the community. Initially, a first user from the community registers on the computer applications service and information representative of the first user is stored in the database. Next, a first transaction record is created in the database from information inputted by the first registered user. The first transaction record includes at least one field representing an identity of a first unregistered user in the community, a field representing a role of the first registered user in the first transaction, and a field representing a role of the first unregistered user in the first transaction.