It is obvious why Firefox does this though; they have no income otherwise like Google does. Firefox users somehow think that using is "supporting" Mozilla/Firefox, but it is not, and they would not pay for the browser, or pay a subscription free. Privacy-friendly ads are a reasonable way for Mozilla to survive long-term -- if they are indeed privacy-friendly.
Ultimately you probably either need a clean-room NGO that ensures the data cannot be de-anonymized, or accept that ad impact counting is BS anyway and only measure profit increases across A/B ad phases.
Ultimately you probably either need a clean-room NGO that ensures the data cannot be de-anonymized, or accept that ad impact counting is BS anyway and only measure profit increases across A/B ad phases.