How Do Push Notifications Work?

Anyone who has a mobile device, and even most browser users, should be familiar with push notifications. These are the little attention-getting beeps that your phone makes to let you know something has happened that you might be interested in: a text from a contact has arrived, you've just exceeded your exercise target for the day, or there's been a comment on your blog post. With so many apps available on so many smartphones, push notifications are a part of most peoples' day, but you might be surprised to know that they have been around in phones since 2003.

RIM was the first to introduce push for their Blackberry devices, allowing your email to be delivered to the Blackberry immediately from the corporate server. They also used the push feature for Blackberry messaging.

It was 6 years later that iOS 3.0 for the iPhone brought the concept of push notifications to the device that was rapidly eclipsing Blackberry devices in popularity. This was quickly followed in 2010 by the first Google Cloud Messaging, and since then there's been continuing additions of capabilities and features to Push Notifications, as well as a spread into other areas of technology, such as the browser and games consoles.

That's a potted history. Now, to the topic, how do these actually work?

How Push Notifications Work

There are three parties involved in getting a push notification to your phone. The first one is the app developer. Apps have to be explicitly enabled to be able to receive push notifications, and the developer will need to add a bit of code that can react to the phone waking up the app to receive the data in the push. The developer will also need to apply to the push service provider—Apple, Google, Microsoft, etc—to get a certificate which is specially signed by the service provider and the developer and associated with the app. Unless you have this certificate, you cannot send a push message to the app. This prevents literal mayhem from occurring—pushes from random agents can't happen.

I've mentioned the second party already - the push provider. In the case of phones, this will be the company that is responsible for the “ecosystem” of your phone, for example, Apple. If you want to send a push to an app, then you must rock up to the push provider, present them with the signed certificate, give them a token (more on this below) that represents the device you want to push to, and the message you want to send. The provider will then take the message and send it as quickly as it can—there can be short delays during busy times, but usually it is fairly reliable. That being said, none of the providers will guarantee that the push gets sent! Their terms of use say it's “best effort”, and that the push may actually never arrive at all. With the billions of push messages that are sent every day to millions of apps, it's not a surprise that a message may go missing now and then.

Well, I've introduced a new concept again—the token—and this leads to the third party that is involved in the process, the push service. Bear with me here. The token is created by the app on the device, and the developer has written a piece of code that will send that token to the  push service. The push service will also provide a way for the developer to lodge the signed certificate with it as well. The push service can then connect with the push provider, and using the token and the signed certificate, deliver the push notification.

In this trio, Swrve acts as the push service for the notifications. We send the push notifications on your behalf, choosing the time where the recipient is most likely to be receptive, even if they are travelling between time zones! We've kept pace with the push notification technology race and can send rich media experiences with great graphics as well as interactive push messages that can have active buttons and controls. We can personalize the content of the push to make the message personal and relevant, and ensure that when you are pushing notifications world-wide that the right language variant is selected. Finally, our all-encompassing A/B testing system will allow to pick the most effective message to send according to the conversion criteria you have chosen.

For more information about push notifications, or any of the other Swrve features that help drive real-time relevance with your customers, schedule a demo with our experts.