They're selling "someone, somewhere clicked your ad". That's it. No other data about you is ever sent.

You seem to be pretty hell-bent on defending Mozilla here. You work for them or something?

Nope. (though for transparency, I have briefly talked to someone who does currently work for them) I just want my browser to continue being funded, and if they can do something that is extremely privacy-preserving that doesn't rely on Google (who gives them the majority of their money) for revenue, then I will be in favor of that existing as an option, and I won't justify acting as though "ping that says someone somewhere clicked this ad" is the same as "we have received money in exchange for giving up your browsing history"

They started out more idealistic, but then they realized that things are expensive and there’s money to be made, so they sold out a little. It happens.

Which is unfortunate. I wish they didn't have to do things like this, because at the end of the day, ads are still ads. I just think that it's silly to say that they are selling your information, when the information being sold is in no way identifying, which is why I think I'm coming off as defensive here. (sorry for that, I'm bad at doing tone in replies online)

The alternative is just Mozilla paywalling features, heavily pushing other in-house ones like their VPN (which is just Mullvad but more expensive), or having to be more dependent on Google, and I don't want that. This just feels incredibly reasonable to me in comparison.