Reaching users at exactly the right moment is crucial to successful marketing campaigns. This can be achieved by segmenting users based on trial activity, personalizing messages with usage data, and emailing users about upgrading just after they attempt a paid feature. To do this, companies need to trigger emails based on actions users take in the product, which can be done by stitching together event and user data in HubSpot. The article provides a walkthrough of how to set up an automated email campaign that sends personalized messages to free trial users when they use a paid feature, and demonstrates how to use custom behavioral events, Workflows, and Census to achieve this goal. By aligning the work of data teams with marketing teams, companies can demonstrate the power of data to impact revenue and build effective campaigns using first-party data.