Amazon SNS vs Google Cloud Messaging vs Pusher Mobile Push Notifications API

In most cases, developers can get started with Amazon SNS by using just three APIs: CreateTopic, Subscribe, and Publish. Additional APIs are available, which provide more advanced functionality.;With SNS you can publish a message once, and deliver it one or more times. So you can choose to direct unique messages to individual Apple, Google or Amazon devices, or broadcast deliveries to many mobile devices with a single publish request.;SNS allows you to group multiple recipients using topics. A topic is an “access point” for allowing recipients to dynamically subscribe for identical copies of the same notification. One topic can support deliveries to multiple endpoint types -- for example, you can group together iOS, Android and SMS recipients. When you publish once to a topic, SNS delivers appropriately formatted copies of your message to each subscriber.;Amazon SNS allows applications and end-users on different devices to receive notifications via Mobile Push notification (Apple, Google and Kindle Fire Devices), HTTP/HTTPS, Email/Email-JSON, SMS or Amazon Simple Queue Service (SQS) queues.;Amazon SNS provides access control mechanisms to ensure that topics and messages are secured against unauthorized access

Versatile Messaging Targets: Distribute messages to your client app in any of three ways — to single devices, to groups of devices, or to devices subscribed to topics.; Downstream Messaging: For purposes such as alerting users, chat messaging or kicking off background processing before the user opens the client app, GCM provides a reliable and battery-efficient connection between your server and devices.; Upstream Messaging: Send acknowledgments, chats, and other messages from devices back to your server over GCM’s reliable and battery-efficient connection channel.;