Comment by hundchenkatze

If you've used iOS or Android within the last 12 or so years then you've almost certainly received push notifications.

Google introduced Google Cloud Messaging [0] in 2007 and Apple introduced Apple Push Notification service in 2008 [1].

[0] https://en.wikipedia.org/wiki/Google_Cloud_Messaging

[1] https://en.wikipedia.org/wiki/Apple_Push_Notification_servic...