We first estimate the relationship between sales and stylistic elements of a review. Prior research in economics and in marketing (for instance, [49]) has associated sales ranks with
demand levels for products such as software and electronics. The association is based on the experimentally observed fact that the distribution of demand in terms of sales rank has a Pareto distribution (i.e., a power law). Based on this observation, it is possible to convert sales ranks into demand levels using the following Pareto relationship: