Notifications are a crucial aspect of modern apps, re-engaging users and building trust, but relying solely on push notifications can lead to critical updates being lost. An in-app inbox provides a persistent record, allowing users to revisit missed information and prioritize updates, creating a seamless notification experience that combines immediacy with depth and context. B2B companies often miss opportunities to create user-friendly experiences by treating notifications as transactional, but companies like Airbnb and Starbucks have successfully integrated push and in-app notifications to improve communication and build trust. By learning from their approaches, B2B companies can improve their notification systems, using techniques such as driving urgency with push notifications, creating a persistent feed of important updates, and personalizing messages through role-based updates. Courier Inbox aims to simplify the process of building effective notification systems, providing real-time updates, cross-platform SDKs, and full customization without unnecessary complexity.