From the same privacy policy you linked:
I don’t personally understand the disconnect between the parts we each posted, but there is a clear disconnect regardless.
And, regardless, this applies to fakespot.com. Not Firefox. Not even slightly Firefox. Firefox unambiguously has nothing to do with selling user data.
Edit: I’ve also gone ahead and sent an email to the address at the bottom of the policy asking for clarification on the issue.
And surely you know better than to assume Firefox’s own privacy policy is null and void because the privacy policy for a different, distinct product offered by the same company has some different terms in it? Regardless of what FakeSpot’s actual policy ends up being (I’m withholding judgement until they reply to my email), I can’t see it as anything other than disingenuous to imply that their policy in some way affects Firefox’s policy. Firefox does not sell user data, period.
I’m going with Mozilla on this one.