"We also work with advertising providers to deliver relevant sponsored content using programmatic technologies. To support this, we may share limited, non-identifying information โ such as device type, IP-derived location information, and category of content viewed โ to help determine which ads to display. ... This data may be shared with our advertising partners on an aggregated and/or de-identified basis."
Mozilla shares device type, location, content categories, and interaction data with advertising partners and marketing partners to serve ads and measure campaigns, even if de-identified or aggregated.