By default the browser checks for available updates, whether for the browser or the add-ons (in the latter case, it's most probable that at least one installed

By default the browser checks for available updates, whether for the browser or the add-ons (in the latter case, it's most probable that at least one installed add-on is hosted in the Pale Moon add-ons site). There's also the sync service, and default start page at start.palemoon.org. You can probably gather some stats from those sources.