Harry Potter and the Order of the Phoenix has more than 6,000 reviews on Amazon.com, and the movie Mean Girls has nearly 5,000. In addition to proving the popularity of J.K. Rowling or Lindsay Lohan, it just goes to show how much consumers like sharing their opinions on the things that they buy.   And thank goodness for consumer reviews because how could consumers possibly shop without them? These days, it seems almost impossible to purchase something without first consulting with...