Google is now rolling out dynamic retargeting to all AdWords retail customers with Google Merchant Feeds and piloting dynamic retargeting in the travel and education sectors. Ads are created with product images pulled from Google Merchant Feed and are created based on an algorithmic prediction for what is likely to perform best based on visitors past actions on the website, including the products they viewed, their purchase history, related and top performing products.
To utilise this feature, you can edit your existing remarketing tag or add the dynamic remarketing tag that AdWords generates. When people visit your site, this tag adds them to one of the remarketing lists and associates the product ID with the visit. AdWords then uses the product ID to pull the product image, name, and price from the Google Merchant Centre account and include them in the ad.