Bests & Worsts Reviews from Amazon

I am more than disappointed in this book, for the following reasons: a) first of all I can't figure out why it has such a high percentage of good reviews, which is what influenced me to buy it; b) the writing is awkward, is in severe need of editing; c) the plot alternates between not making sense and being boringly predictable; d) the ending was preposterous. I just wish I knew of a way to avoid falling into a pitfall like this again when reviews appear to be so good for a book.