Google Cloud Messaging (GCM) is a technology that provides simple and reliable messaging to devices. In the last six months, the number of messages that GCM handles has more than doubled — to 150 billion messages per day, and the number of applications has grown 25% to 750,000. With this growth in mind, we’re continuing to improve the service with some helpful updates for developers.
Google Cloud Messaging supports topic messaging – an easy way to segment your users’ devices into groups and send a message to the entire segment at once. We’re now happy to announce that we’re allowing unlimited free topics for your app. This means app developers can place an unlimited number of devices within each topic and create an unlimited number of topics.
Moovit uses topics to efficiently scale
Moovit, a community of 30 million+ users, helps improve transit routes in cities worldwide. Using GCM, Moovit has been able to create over 60,000 topics to help users in individual cities navigate the headache of daily transit.
“We started using GCM to power our push infrastructure in a more seamless, efficient way. Not only does GCM help us to send real-time updates to a high volume of tens of millions of users, keeping them informed of any transit information they need for a stress-free commute, but we don’t have to spend extra time or energy developing an infrastructure for delivery on the backend. GCM Topics allows us to message users in hundreds of cities around the world with multi-platform support for both iOS and Android.”
For example: Users of London’s Underground Service were impacted by recent strikes that disrupted the regular service. While Moovit has a global audience, only those impacted were notified, as Moovit used GCM topic messaging to send the message to only those that needed it.
National Public Radio (NPR) uses Topics for news personalization
NPR is a mission-driven multimedia news organization and radio program producer in the United States. To reach their users efficiently, NPR sends and schedules personalized notifications to their listeners
via their NPR One App. For example, if you listened to the Aziz Ansari interview on the show All Things Considered, and wanted to hear more, you could subscribe to the topic ‘Aziz Ansari’ and receive a notification of his appearance on the Hidden Brain podcast. Similarly, you could subscribe to other topics such as Election 2016, Women in Combat or Pop Culture Happy Hour.
Tejas Mistrly, Mobile Product Manager for NPR, described their use of topics: “With GCM topic messaging, NPR is able to send and schedule personalized notifications to our listeners on NPR One. Whether to catch them up on the latest news or to tell them a story from a recommended podcast across public radio, GCM topic messaging gives us the tool set to send the most effective notifications that ties into our personalized radio app.”
New APIs for GCM topic management
Complementing unlimited free topics and the existing client-side API, we’re launching a new suite of server APIsthat allow you to manage message subscriptions. The new APIs allow you to subscribe/unsubscribe devices individually or in batches, as well as allow retrieval of info on current subscriptions per device. We think the server-side API is a great tool to help you reduce roll-out friction, and allow for easy management and migration of subscriptions as your app grows.
To learn more about Google Cloud Messaging, visit the Google Developers Site, where you can learn more about how to build for this technology, and download sample implementations. There’s also a full reference implementation available on GitHub and the GCM Diagnostics tool for when you need help to troubleshoot.