Push notifications are messages that are sent directly to users' device. They appear on lock screens and are added to the notification alerts on a smartphone or tablet.

They are a powerful tool to increase user engagement. The biggest social media apps like TikTok and Instagram send their users notifications all the time. It works as a part of their reward system — for example, a notification that a friend liked users' picture gives them a little dopamine boost and gets them to return to the app.

However, more doesn't always translate to better — especially in the case of push notifications. Think of them as tapping users on the shoulder. It's fine if you have something important or relevant to say. If not, you'll only annoy users, and they might turn off notifications altogether or even uninstall your app.