Dislike in Retail

What does a dislike button mean in retail?
Facebook indicated last week it was close to testing a "dislike" button, or at least one that expresses empathy, to sit alongside its thumbs-up "like" button, promising both benefits and risks for retailers. Would the arrival of a dislike button on Facebook be a net positive or negative for retailers and brands?  .... "

And further, a look into the value of a 'dislike'.  Depends on the context.  A better understanding of embedded emotional reaction?  Good piece with a number of interesting connections.