Send Automated Messages, Deliver Results. With Customer.io, you can send targeted emails, push notifications, and SMS to lower churn, create stronger relationships, and drive subscriptions. Design experiences to create more paying subscribers, and help people get value out of your product or service. Segment audience based on real-time events. Create sending logic in the web browser rather than writing hard-to-maintain code. Build, measure, learn. A/B test your campaigns and understand how each message is performing.