ActiveCampaign is an all-in-one marketing hub that combines email newsletters, marketing automation, and a CRM, allowing users to store customer information in one place and track their marketing efforts. The app enables marketers to segment their contacts based on different criteria, create personalized emails with its drag-and-drop editor, and set up nurture campaigns to keep leads engaged over time. With conditional logic, users can map out when contacts should receive certain emails or special offers, making it easier to onboard new customers and keep existing ones warm until they're ready to buy.