Every individual who registers on an eBay marketplace has a unique eBay user ID. Additionally, other information about each eBay user is kept by eBay, such as registration date, Feedback data, eBay Store information (if applicable), and standing with eBay. The GetUser call can be used to retrieve information about a specific eBay user.

Users can control many aspects of their eBay experience through preference settings. These settings can be made through the user's My eBay pages, or settings can be changed or retrieved through the SetUserPreferences or GetUserPreferences calls. Refer to User Preferences for additional information.