Simple Notification Service.
- Highly effective - Gets cheaper as you use more
- Highly-available - Messages are stored redundantly across multiple AZs
- Push Based
- You can push notification to major mobile devices (iOS, Android, BaiduPush, FireOS)
- You can also push notification by Text Messages (SMS), SQS, Email, HTTP endpoints
- Topics - A grouping of messages for receivers to subscribe to, e.g.: "push notifications about X"