A user review is one written by someone for a product or a service based on his or her own experience with the reviewed product. Popular sources for consumer reviews are e-commerce sites like Amazon.com or Zappos. Social media sites like TripAdvisor and Yelp contain user reviews. E-commerce sites often have consumer reviews for products and sellers separately. Usually, consumer reviews are in the form of several lines of texts accompanied by a numerical rating. This text is meant to help shoppers make a decision about a product. A consumer review of a product usually has comments on how well the product meets a user's expectations. It talks about how well it does its job, how reliable it is and its quality for the price. Consumer reviews are also called word of mouth. Users also comment on how they were treated by a seller. They may comment on how dependable or trustworthy a seller is.