AGGREGATING PRODUCT ENDORSEMENT INFORMATION

A “likeness factor” indicating users' endorsements of a product is disclosed. “Likes,” “dislikes,” and other favorable or unfavorable user input for a product are collected from a website that displays the product and that logs such information. The collected information is made available on other websites displaying the product either directly or in the form of a likeness factor. The information can be aggregated from multiple websites and sources. A likeness factor for a manufacturer or other merchant is based on likeness factors for products of the manufacturer. Changes in likeness factor over time indicate a trend for products and manufacturers and can be used to predict product performance. Search results are filtered by likeness factor, and advertisements are presented based on likeness factor.