Dear Log,
Random silly idea:
A statistical measure of the (in)sanity of the Amazon reviews for a particular book is the degree of "bimodality" of the stars it gets -- i.e., the extent to which all reviews are either 5-stars or 1-star, with little or nothing inbetween. The unit of this statistical measure can be called "the Sussman", after one of the authors of SICP which for the longest time had an almost perfectly and symmetrically bimodal distribution -- half the reviews were 1, half were 5, and there was basically nothing else.
