#2 shouldn't be a hard and fast rule, especially, with respect to textbooks and, especially, when it comes to subjects like math. A student rating a phenomenal

#2 shouldn't be a hard and fast rule, especially, with respect to textbooks and, especially, when it comes to subjects like math. A student rating a phenomenal book 2 stars because "...it was assigned and we had to buy our book. But the book is too hard to understand, explains jack shit and totally worthless. I give it two stars only because I bought it at 1/4 the price on sale, otherwise this book barely deserves 1/2 star at most. Believe me, I am not dumb - I sometimes even read straight out the textbook." is not rare. I read comments only after I'm done with the book.