How does Mozilla calculate daily users in the statistics panel?

Add-ons Development
1

I’m a new add-on developer trying to understand the stats panel. For context, my add-on was first published around December 12th.

I’ve noticed a persistent discrepancy: the downloads from the Mozilla add-ons page don’t add up to anywhere near the number of active users. My stats show only a handful of downloads over the past week, but daily active users have been climbing steadily, sometimes by 20 per day, and I’m now at 70+ users with only approximately 25 total downloads. If anything, I would have expected the opposite: more downloads than active users.

Two questions:

  1. How does Mozilla calculate daily active users for the statistics panel?

  2. Should I be concerned that someone is redistributing my add-on elsewhere? Specifically, if my add-on were hosted on a third-party site, would those installs still appear in my user stats? Does telemetry or some other mechanism capture users who didn’t download directly from AMO?

2

There isn’t a ton of information available on the exact meaning of these values. One of the few resources I found is a pair of blog posts from 2020:

These posts say that AMO’s stats are derived from Firefox’s telemetry data, and that download stats are only recorded when the download originates from addons.mozilla.org. I don’t know if an installation triggered by syncing a user’s Firefox profile would be counted as an AMO download.