I have really mixed feelings on this.

On the one hand, I have to be pragmatic. The truth is that the internet kinda needs at least some ads to be viable. Hosting stuff and creating stuff isn't free. It needs to be paid for somehow, and I doubt people are willing to pay a fee for each site they visit (not that the infrastructure exists for that anyway!)

Accepting that undeniable truth, I guess we should push for ads to be as uninvasive and privacy respecting as possible. Which is what this project is.

If this takes off, it would certainly be a net positive, and it could even pressure the likes of the EU to force Google/Meta/others to adopt the same kind of thing. It would also be good from the perspective of Mozilla lessening their reliance on Google.

That said... I can't help but feel Firefox is playing with fire here. A lot of their users hate ads (same, ublock origin ftw), and they might view getting involved with this very poorly, risking Firefox losing even more market share.

And I know the ads will be private, but despite that I think any ad associations at all with Mozilla products risks undermining that reputation.

They should be very cautious with this.