A Product Feed is a file that lists up-to-date information about your current products. You can submit a Product Feed in a .csv file format with columns separated by tabs or an .xml feed.
Your Product Feed can populate ads dynamically. This allows us to retarget your customers with ads specific to the products they have viewed most recently on your site.
See the article Placing Tracking Codes for details on how to modify your tracking code if you are using a product feed.