February 2019 Summaries

Firebase Cloud Messaging (FCM) accepts messages for individual devices or large topic audiences, but a successful API response only confirms that FCM has begun delivery attempts rather than that a device received the message. FCM retries delivery until a message expires, up to 28 days by default, is replaced through a collapse key, or is associated with a device known to have been offline for more than a month, in which case pending-message deletion notifications may be sent when the device reconnects. Delivery is affected by connectivity, message priority, battery optimization, and platform-specific restrictions. On Android, Doze mode, app standby buckets, background limitations, user-imposed restrictions, and app uninstallation can delay or prevent delivery, while invalidated tokens subsequently return NotRegistered errors. On iOS, FCM commonly hands messages to Apple Push Notification service, which then controls delivery, or can use a legacy direct channel for data-only messages that queues messages until the app reconnects in the foreground. Web delivery may be subject to Android restrictions or delegated to browser-specific push services, and developers can use BigQuery exports or FCM reporting tools to analyze available delivery data.

Google Analytics for Firebase enhanced its audience builder to help marketers better understand and act on user behavior across mobile apps. New capabilities include dynamic audience evaluation that automatically adds or removes users as they meet or cease meeting criteria, exclusion rules for more precise segmentation, and membership durations that keep audiences timely. These features enable businesses to identify groups such as first-time app visitors who abandon shopping carts within a 30-day period, then target them through in-app promotions, notifications, email, or Google Ads while automatically stopping outreach once they purchase or become ineligible. By making app audiences more flexible and actionable, the updates aim to improve personalization, marketing investment decisions, customer experiences, and app growth.