Customer.io

Customer.io is a platform for building personalized customer journeys across channels, turning customer data into targeted experiences via email, push notifications, SMS, and in-app messaging, trusted by named customers including Notion, Buffer, Monarch Money, and Attio. An automated journey builder now includes AI agent capabilities, audience segmentation runs on behavioral data, a Design Studio handles message creation, and analytics track performance across channels with data-integration tools for connecting existing systems. Documented customer results include an 80% billing renewal rate for one client and a 4.4% engagement boost for another. No pricing is shown on the main page; a separate pricing page covers plan details. Good fit for a product or marketing team that wants behavioral-data-driven customer journeys spanning email, SMS, push, and in-app messaging in one connected platform.