I appreciate your informed response but no system other than advertising-abstinence is fool proof.
Im saying this as a supporter. My browser of choice is firefox and I send them money regularly. And I understand their need to generate more revenue. But there has never been a company who has sold customer data discretely. My understanding is that every piece of data that's sold can be de anonymized when combined with other data sets. And the data is horsetraded until it gets into some very marginal actors' hands.
Mozilla's need for money is largely driven by massive mismanagement. It should have been fully funded in perpetuity through establishing a foundation that operates off interest payments but they decided to try and build a headquarters in Mountainview. They also operate offices in some of the most expensive cities in the world. They have made expensive software aquisitions. These are not necessary and have only whetted mozilla's thirst for other revenue sources. It's guaranteed that they will look for more customer data to sell because that's the path of least resistance.
I wish them luck but I also wish they'd not chase advertising money.
I think you're right and that I've horribly misunderstood how this data is collected and used. According to their yearly report, mozilla's advertising revenue is explicitly not drawn from user data and is only related to tiles and default search engine sponsorships. The fact that they are not selling this information is heartening and it inspires confidence that they have not flipped on the ad money spigot.