Applications can retrieve data from the eBay marketplace to be displayed in its user interface or to otherwise be processed by the application. Items can be retrieved as a group (e.g., a list of the items a particular seller has listed,) or individually (e.g., similar to the View Item page on the eBay marketplace).
One reason an application returns the data for an item or group of items is to display the item data in a visual format. The application's end user could then see the data and use the information as the basis for taking some action, such as a seller revising the item or a buyer making a bid on the item.
Another reason for retrieving item data is the programmatic processing of item data outside the context of a user interface or human intervention. For example, an application could retrieve a list of items for a particular seller for the purpose of assessing bidding activity, only alerting the seller should a predetermined condition exist (e.g., the end of the auction is near and there is a current high bidder).
Applications call:
- GetItem to return data for a single item
- GetSellerList to return a list of items for a specified seller
It is typically more efficient to call GetSellerList to retrieve a list of items and operate on them than it is to call GetItem multiple times. Doing so saves on the number of API calls made by an application.
Note: In general, the number of calls issued by an application is limited on a daily basis; a few calls are limited on an hourly basis. Refer to API Call Limits for complete information.
Additionally, calling GetSellerList reduces the total online time spent communicating and interacting with the eBay marketplace.