A Back in Stock alert is an email announcing a previously sold-out product is once again available for purchase. Emails only go to shoppers who register to receive an alert for the specific product. For example, if your gold picture frame inventory sells out and someone signs up for the restock update, you do not have license to send that person Back in Stock emails for silver picture frames if they are not subscribed. Restock automations are great for engaging customers by informing, building trust, and increasing sales.