Why do your Push notifications go undelivered?

April 15, 2021
Mobile push notifications are the most in-demand and fastest-growing customer engagement channel today. The main reasons for this high demand are:

  • low cost of Push, often free;
  • high response rate.
Push notifications are not a guaranteed delivery channel. Moreover, the problem companies face when launching Push services on their own lies with the delivery rate, which typically ranges from 50% to 70%. That is, 30% to 50% of messages will either not be delivered at all, or, if the company has the necessary fallback technology, will be re-sent via SMS or other fallback channels. This significantly increases costs, which can run into tens of thousands of dollars per month for major companies.

The result is that a company can use a free and more efficient (in terms of response rate) communication channel – Push notifications – but cannot ensure delivery of most of such messages.

So what could be the reasons why users are not receiving your mobile push notifications?
Features of Chinese-manufacturer devices
Android mobile devices are produced by so many manufacturers in China who optimize self-sufficiency (battery), performance and other characteristics of their devices in every possible way. That's why the app activity in the background may be limited. If the app is running and is in the device's memory, then notifications will be delivered. But the phone is not in use most of the time and if the app hasn't been launched by the user for a long time, delivery issues would redouble.

Issues with push delivery to various Chinese-manufacturer Android devices have been confirmed by numerous articles containing guidelines for users on how to configure their devices. But improving the delivery rate in general is a much more difficult challenge that requires highly specialized expertise, significant effort and resources from the developer.
Network issues
If a device doesn't have Internet access, Push notification will not be delivered. Cloud Push services for Android and iOS mobile platforms take into account situations where the device does not have Internet access. The message is queued up for a while and is sent when the device comes online, unless it has expired or has been replaced by other messages.

Certainly, the sender has no influence on the recipient's device gaining access to the Internet. However, you can influence message delivery when the device comes online. This is important since mobile network coverage and Wi-Fi access are not available everywhere, and intermittent absence of Internet on the device is a normal situation.

Besides, in some cases, the operating system may restrict network access for a particular application. This can result in Push notification not being delivered, arriving late, or delivery information not being transmitted by the app to the sending server. Such issues have solutions deployed on the mobile app side, and they should be actively implemented.
Operating system versions
Over time, we've noticed that Push delivery rates can vary across different OS versions. This often correlates with power consumption optimizations and improvements on the functionality of Push itself. OS innovations can reduce message delivery rates.

So, the release of new versions of mobile OS can either increase or decrease Push delivery rates. Either way, maintaining a high quality Push service would require the developer to monitor innovations and apply best practices in good time.
Disconnection of vendors from Google services
By the end of 2019, Google had shut down access to its services for Huawei. This also affected Push notifications. Consequently, Huawei devices, including its Honor sub-brand released after November 2019, stopped receiving Push messages via Google's Firebase Cloud Messaging. Sending Push notifications to a fairly large segment of Huawei devices has been disrupted..

Huawei launched its own Push service, which, along with Apple Push Notification service and Firebase Cloud Messaging, allows you to fully send Push messages to the company's devices.
Inability to send delivery status notification
It’s not enough to just deliver a Push message, you also need to know its delivery status. There are situations where a Push notification is considered undelivered, although it was actually delivered to the device, but the app was unable to duly notify the sending server.

Delivery statuses are needed when using fallback channels and for assessing the effectiveness of marketing campaigns. If a non-delivered Push message is sent via SMS or another channel, and you don’t receive a delivery status notification, the company incurs additional cost. It will have to pay extra for sending the same message via SMS, even though the message has already been delivered to the recipient via Push.

Absence of Push notification delivery status is an important reason for low delivery rates. It needs to be thoroughly analyzed and appropriate action taken.
User App usage profile
Interestingly, delivery rate is also influenced by how the user uses his app. How often does he launch the app? How long has the app been installed? Does the user respond to a Push notification by going from the notification to the app – swipes or simply ignores.

This is because the Android OS tracks the user's actions with the app and prioritizes the app accordingly.
Background app activity
The way an app is designed or, more precisely, the actions the app performs while in the background, also affects push notification delivery rates. For example, if an app is actively using the Internet in the background, the operating system is likely to limit its activity or block it completely in order to conserve the device's battery.
How to increase Push notification delivery rates
There are a number of practices that will ultimately raise the percentage of your delivered Push messages to 90% or more. This requires an entire development team dedicated to this very issue, finding problem areas, experimenting, applying solutions, evaluating the results, and so on.

The best option is to implement a ready-made, proven solution that is guaranteed to provide a high percentage of Push delivery , for example, the WINGS Notification Server .

In the next article, we looked at and compared the various Push implementations .