A computer-implemented system and method for generating an interest profile for a user from user generated content on existing online profiles is provided. Interest categories are maintained in a database and each interest category is associated with an initial interest index score. User generated items are selected from an existing online profile and each user generated item is associated with a weight. For each user generated item, similarity mapping is performed with each of the interest categories in the database by extracting artifacts from each user generated item, calculating an artifact similarity score for each of the extracted artifacts, obtaining a user generated item similarity score for the user generated item, and determining a current interest index score for the user generated item. An interest profile for the user is generated by applying the current interest index score to the interest category.