1. A system for electronic trading, comprising: a memory having stored therein: a plurality of users associated with a game controller, the plurality of users comprising a first user and a second user; a first set of controller signal relationships associated in the memory with the game controller and the first user; and a second set of controller signal relationships different from the first set, the second set associated in the memory with the game controller and the second user; wherein each controller signal relationship associates one of a plurality of game controller signals with one of a plurality of transaction commands associated with electronic purchasing; and a processor communicatively coupled to the memory and operable to: determine that the first user is using the game controller; receive a particular game controller signal from the game controller; based on the acts of determining that the first user is using the game controller and the act of receiving a particular game controller signal from the game controller, access the first set of controller signal relationships; determine the transaction command associated with the particular game controller signal based at least in part on the first set of controller signal relationships; and communicate the determined transaction command, wherein a first joystick of the game controller is configured to move a cursor in a user interface, wherein a transaction can be entered at the user interface for entering transaction commands, and wherein a second joystick of the game controller is configured to input transaction commands in the user interface.