Thanks, I didn’t know that web bots are counted. These reasons apply to all add-ons, so I’ve checked the numbers of some other add-ons whose stats are publicly available. It turns out that what I see is quite common. It’s actually common for one download to cause less than 0.1 daily users (looking at all-time downloads).
- AdBlocker Ultimate: 4.6m downloads, 0.38m daily users = 0.08 daily users per download
- The Camelizer - Price Tracker: 0.42m downloads, 0.038m daily users = 0.09 daily users per download
- Google search link fix: 1.3m downloads, 0.06m daily users = 0.04 daily users per download
- Youtube Best Video Downloader 2 - MP3 MP4 1080P: 3.7m downloads, 0.1m daily users = 0.02 daily users per download
- Status-4-Evar: 1.8m downloads, 0.1m daily users = 0.05 daily users per download