There are a number of reasons why it makes sense to use PubNub in addition to, or instead of, push notifications (such as Apple APNS or Google FCM):
- Application is deployed across multiple devices from different vendors, including iOS, Android, etc.
- Developers require ease-of-integration and a consistent interface and behavior across these diverse devices
- Push notification networks generally cannot acknowledge message receipt (no bi-directional communication)
- Message payload contains sensitive data which PubNub can deliver securely (SSL) as well as encrypted (AES)
- Message sizes are restricted to 4KB (GCM and MPN S) or 2KB (APNS) whereas PubNub supports up to 32KB
- Missed messages can be retrieved using PubNub's Storage & Playback and the history API which is not possible with mobile push notifications
- You can detect who is online with PubNub Presence
- ... and much more.