A method and a system are described for catalog generation based on divergent listings. For example, a listing module may receive a divergent listing and collect data corresponding to an item in the listing. Each divergent listing of an item for sale is divergent with respect to other listings of the same item for sale. A calculation module may calculate an entropy value based on the collected data, the entropy value indicating a degree of difference between the item in the listing and a product in a catalog. A catalog module may associate the listing to the product in the catalog based on the entropy value.