A recent TechCrunch article refers to the seminal experiments of Ivan Pavlov. If by some chance you weren’t aware of his work, he showed how the sound of a pre-dinner bell triggered his dogs to salivate at the imminent prospect of food. You can imagine their excitement when they heard that tinkle, waiting for their juicy bone!
I’d like to continue that conversation around the psychology of push notifications, but I want to focus on the sounds themselves, rather than their timing or their message per se. As a marketer, when you send individual emails or SMS, you don’t have the power to configure that message to make a particular sound. However, you do have that power with push notifications sent to mobile apps. So it should be used wisely.
Sounding It Out
There are 3 approaches to take. You can decide that the push notification will be silent. This means it will simply appear on the users screen with no accompanying sound. So if the phone is in their pocket or out of sight, it will wait for when they’re next ready to check their phone. It is well regarded that this is the best way to communicate non-important messages - although as a side-note, if your message is really ‘non-important’, why are you sending it?
You may decide to send the notification using the default sound of the device. Then it will get mixed in with all the other notifications from SMS, email, Facebook etc. The sound itself will draw the user to check their device, so you need to ensure that the message itself is worth the “who’s that from?” question. In some ways, this is the most dangerous sound to use. There’s a risk that the dogs have heard the bell, they’re expecting steak and instead they’re served chicken!
The final alternative is to use a custom sound that is recognisable for your app. Let’s take the BBC news app. It’s fortunate enough to have a jingle that those of us who watch TV on this side of the Atlantic (I’m in Ireland) will recognise. So when a user hears that jingle, they’ve immediately learnt that it’s a BBC news update, before they’ve read anything or looked at their phone.
But the use of such sounds doesn’t have to be the reserve of big news apps that benefit from multi-channel exposure. Any app that uses sound within it’s normal flow can experiment with using these sounds to signal notifications to their users.
Facebook is also starting to experiment with introducing sounds within its app. Remember, by using your signature sound, you want that sound to convey important news for the user, not simply a random broadcast. If you’re a gaming app, it may that your character or domain has been challenged. If you’re a dating app, it may signal that someone has winked at you, or your wink has been returned. If you’re a betting app, you may have won at the races. Sports apps can use these custom sounds to signal your favourite team has won or scored a goal (or touchdown for those across the pond).
And of course, don’t be shy to use 2 or 3 different custom sounds that are identifiable with your app, each representing something different. This scenario is most applicable in apps that have concrete categories of push that would go out regularly to users.
It is important to recognise that the use of sounds should probably only be used with engaged users. If you’re broadcasting a general message to a wide audience, the use of a sound and the raised expectations that go with it may simply annoy more users than it informs. And annoying users, especially those sitting on the fence, can easily lead to uninstalls - which are far easier for the user than turning off notifications.
In the worst case, if you’re targeting lapsed users of your app with a re-engagement campaign to entice them back, be careful how you construct the message. We’d recommend sub-dividing that audience further. Send one message to those lapsed users who used to be very engaged with your app. They might appreciate your familiar jingle and you can word the message appropriately. However, previously infrequent users are very unlikely to respond to a sound well and we’d recommend the silent push.
But don’t take my word for it. Swrve would recommend that you A/B test everything, and not only can you A/B test the message, we’d recommend you also test the presence or absence of a sound, and what type of sound. This allows you to safely compare between randomly selected users of the same audience, and then measure the re-engagement rate with the app, and any downstream metrics such as number of subsequent sessions, minutes in app, feature usage, purchases etc.