one industry norm that makes these things tough (again, not Mozilla's fault) is that at least under US law, Mozilla could change its privacy policies at some point in the future and do a lot more than it currently does.
and... my parent comment was brash and probably deserved the downvote it received.
Selling user data would be completely against our mission and values, and I think it would be extraordinarily hard for such a change to make it through the internal immune system for such things. I think Mozilla is less likely to do bad things with your data than just about any other company (or government for that matter) out there.
(Disclosure: I work for Mozilla. I am helping write an updated set of privacy guidelines for engineering teams, to be as explicit as possible about how careful and respectful we need to be with data.)
We never got authorization from individuals to do that correlation.
We aren't perfect, but I think we do a pretty good job of respecting and protecting your privacy at Mozilla.