Identifying highly engaged subscribers involves tracking several key performance indicators (KPIs): - Open Rates: The percentage of subscribers who open your emails. - Click-Through Rates (CTR): The percentage of subscribers who click on links within your emails. - Conversion Rates: The percentage of subscribers who complete a desired action, such as making a purchase or signing up for a webinar. - Engagement Over Time: Monitoring how subscribers interact with your emails over a longer period can reveal consistent engagement patterns.