Earlier quoted context omitted.
I think they're trying to make the distinction between "we sell your searches and clicks attached to your personal id" and "we sell derivative aggregated information like we have a lot of users of X style to advertise to". But it's kinda hard to sift through exactly what they can and can't sell under this.
Wouldn't derivative aggregated information not be included in definitions like the one quoted because they specifically about personal data? If you sell the information how many customers you have and how many shoes you've sold last month, are you selling your customer's personal data?
To make that analogy fair for the scope of what Mozilla's doing, the shoe store would have to be selling data about what color shirts people are wearing when they visit the shoe store.