How to create an XML product feed
From Spiffy Stores Knowledge Base
Warning: This information is now obsolete and should not be used.
Please refer to Product data feeds for the current information on creating and managing product data feeds.
Setting up an XML feed for your products is a great way to get added exposure for your online store by syndicating them to a variety of shopping portals.
An XML feed is a means to publish frequently updated data in a consistent data format. With product listings, that data is the product name, price, description, manufacturer, photo URLs, etc.
Since the data is in a standard format, it can sometimes be used by other sites to populate their databases of products on your behalf — automating the otherwise manual task of data entry that would be required to place your products on those sites.