1. A method comprising: sending a connection request, from a seller application executing on a client machine, to a network-based transaction facility, the seller application being customizable and being customized by receiving configuration information from the network-based transaction facility, the configuration information including a hierarchal product category structure for generating a listing for a product for sale; receiving, by the seller application, a current version of the configuration information from the network-based transaction facility; sending, by the seller application, configuration confirmation to the network-based transaction facility, the configuration confirmation indicating the seller application is configured using the current version of the configuration information including the hierarchal product category structure; and sending a request for a transaction listing, the transaction listing being generated based on the current version of the configuration information.