Just to add a little something to Jeneane's answer - One of the things that hooked me about Gonzo was the vivid contrast with traditional marketing techniques, like broadcast advertisements (which, on the net, we call SPAM).
These are made by people who don't use the product, usually don't know that much about it, certainly won't tell you about any flaws it may have or give an honest appraisal of its relative worth (vis a vis any competition for example), and are simply paid to say nice things about it loudly.
Gonzo is all about the voice of experience. Check out the examples that Chris uses for his suggestions of patronage; you'll see that while he encourages Ford employees to talk about how a Ford truck might relate to their gardening hobby, there is no suggestion that they ought to toe any particular party line.
On the contrary, he clearly and repeatedly stresses that any such editorialising would render the exercise almost completely futile. The voice must be engaged, and therefore it must be genuine, it must be human, and it must be free of imposed agendas.
Only then can listening to it be of maximum value, only then can it be Gonzo.
Objectivity is not the objective (pun intended, sorry!). In fact it may be entirely irrelevant, except in the sense that in Gonzo it is not pretended to, as it may be in other marketing techniques.
I would say that it (objectivity) is surely possible, I suppose that many an art critic would consider themselves objective, even though fully engaged in the Gonzo sense.
"Art critics create nothing, and thereby feel themselves qualified to judge the works of creative people. There is logic in this: they hate all creative people equally." --Robert Heinlein