"When you click on a sponsored tile, Firefox sends anonymized technical data to our partner (https://www.admarketplace.com) through a Mozilla-owned proxy service (https://github.com/mozilla-services/topsites-proxy). This data does not include any personally identifying information and is only shared when you click on a Sponsored Top Site."
@andreas I don't get this. Isn't what ad tech companies want and promise to provide "personalised" data and ads? Why would they want anonymised data? What do they make of "someone somewhere clicked a link"? Don't they want to know your PII specifically?
They are also obscuring what data is shared, intentionally or not. There's no info in that repo regarding what they share but https://support.mozilla.org/en-US/kb/sponsor-privacy links to it suggesting that's where that info is found. But apparently it just relays data.
Personal instance of nitrohorse (nitrohorse.com).