A method, system and computer readable storage medium for reporting on a measured change in a consumption rate. Media consumption histories for a plurality of entities are received. A monitored audience is selected from the plurality of entities by selecting entities which have completed an online purchase. A category value for each of two or more categories of media content is determined. One category of media content includes one or more items of media content. One category value represents the measured change in consumption rate for one category of media content for the monitored audience between at least two time intervals. One consumption rate is determined based on the number of times each item of media content in the one category has been delivered over a network during one time interval. A report including a reference to two or more categories and their associated category values is generated.