There's a myth going around that Firefox blocks analytics providers in its default configuration. For example, in a recent HN discussion 5% of the comments were people asserting it did, and another 5% were people responding to them to assert that it doesn't. To confirm, it doesn't:

You can test this yourself:

1. Open Firefox

2. If you've added any extensions create a fresh profile, so you can test the default configuration

3. Open Developer Tools

4. Open the Networking panel

5. Visit a site with analytics (ex: jefftk.com)

6. Observe pings being sent (ex: google-analytics.com/j/collect?...)

Firefox does have an "Enhanced Tracking Protection" mode, but it's not enabled by default. Additionally, Firefox users are likely disproportionately blocking ads, which also block analytics scripts.