1. An on-line shopping method, comprising: accessing by a transacting partner user, via a sales engine executing on a processor, a product catalog of a shopping system; accessing, via the sales engine, a partner database storing data in a hierarchical node/tree structure identifying a plurality of partners, which are business entities, entitled to use a shopping system, wherein a transacting partner at a first node position in a hierarchy is entitled to place orders on behalf of partners at nodes that are child nodes to the first node; identifying, to the transacting partner user by the sales engine, which other partners from the plurality of partners on whose behalf the transacting partner user is entitled to place orders based on an analysis of the partner database by the sales engine wherein a transacting partner's entitlement to order on behalf of other partners is based on the transacting partners position in the hierarchical node/tree structure of the partner database; and authenticating a transacting partner user's entitlement to order from a product catalog on a shopping system based on the results of the identifying.