Understanding Notification Delivery

Web push notifications are delivered to a subscriber’s browser. Each browser has their own delivery service for this - Chrome uses Firebase Cloud Messaging (earlier called Google Cloud Messaging) while Safari uses Apple Push Notification Service.

The notifications that are pushed via iZooto can be viewed under Campaign Reports.

Audience Reach

This shows the audience count at that particular time when the campaign was pushed.

For recurring campaigns, this would be a cumulative count of all the runs so far.


After a notification is pushed by the user, the iZooto server pushes them further to the FCM and APN servers. They respond by accepting the notification for those subscribers who are still active and provides the actual count to whom the delivery would be made. For instance, let’s say the notification was pushed to an audience of 100. If FCM replies back saying that the actual count (at that precise time) is 98, the ‘sent’ column in the notification report would show 98. Delivered doesn’t mean that the subscriber has viewed the notification.

For recurring campaigns, this would be a cumulative count of all the runs so far.


CTR (Click Through Rate) is the number of clicks received on a notification divided by the notifications delivered. This is usually the metrics marketers use to analyze the effectiveness of any campaign. CTRs also depend on various factors - Content, timing, audience, and frequency of notifications sent. The clicks and CTR keep getting updated on the report.

Notifications are delivered to the subscriber even when he/she is not on the website. Here is where they get delivered/stacked:

  • Windows - right above the taskbar
  • Mac - Mac OS notification center
  • Linux - top right section of the browser
  • Android - notification tray

We send notifications in batches of 10,000. This means that if you are pushing a notification to 25,000 subscribers, it would get sent in 3 batches - 2 with 10,000 subscribers and 1 with 5,000 subscribers.