Google has announced that product ratings are now available globally. Product ratings appear on Google Shopping ads and show users how other people have reviewed the product, using a 5-star rating system. Product ratings will now appear in all countries where Google Shopping is present. Ratings are pulled automatically from a range of sources including users, merchants, editorial sites and third-party aggregators. If you want product ratings to appear on your Google Shopping ads, then you need to set up a Merchant Centre account for your store and then upload Product Ratings feeds.