16. The system of claim 15 , wherein the aspect determination module is further configured to, in response to determining the at least one most relevant aspect name for the category, sort the determined demand scores for the at least one most relevant aspect name to determine at least one most relevant aspect value for the at least one most relevant aspect name.
15. A system comprising: a compilation module to compile historical data, the historical data comprising user behavior data based on actions performed by users and configured to access listing data, the listing data including aspect data for each listing; a data joining module to join the user behavior data with the listing data and a determined category of each listing to create a single table comprising joined data, the joined data including the historical data, the listing data, and the determined category for each listing; an aggregation module to determine demand scores based on the joined data by aggregating over the joined data to define the demand scores; and an aspect determination module, comprising a processor of a machine, to sort the determined demand scores to determine at least one most relevant aspect name for a category, a message indicating the at least one most relevant aspect name for the category and suggesting providing an aspect value that corresponds to the at least one most relevant aspect name being provided to a user that is currently creating a new listing.