1. A method comprising: at a network-based commerce system, opening a number of network connections, the number of the network connections determined by a client application locally installed on a client machine based on a machine census of the client machine, the machine census including determining a central processing power, total memory, available memory, bandwidth, and operating system, and a records census, the records census based on a number of items to synchronize between the network-based commerce system and the client application; receiving, via the network connections and from a user at the client application, first update data related to a user listing of the user; receiving, via the network connections and from the client application, a synchronization command that synchronizes updating of data related to the user listing of the user, between the client application and the network-based commerce system; responsive to the receiving of the synchronization command, updating a first record related to the user listing, the updating to include the first update data received from the user in the first record; and communicating, via the network connections, second update data to the client application, the second update data reflecting a further update to the first record related to the user listing.