Evidently, Amazon doesn't delete ALL one-star reviews. That makes me wonder who's in charge of the amazon pages.
It seems like they keep the reviews rated as helpful over the ones rated unhelpful. It would be interesting to experiment and see if a five-star review will get deleted with overwhelming "unhelpful" votes.
Although keeping the review count at 101 is really weird. I don't know why they do that.
I used to go over there and rate all the 5 stars for Sandworms as unhelpful everyday but I got bored with it.