Abstract: An engine (1601) for link building in order to improve the visibility of a website to search engines is disclosed. Back links are generated that represent links from other websites, such as directories, to the website under consideration. Prospect directories are identified by identifying volumes of candidate directories and initiating an iterative search of these candidate directories. Candidate directories are dismissed that are already under consideration. Candidate directories are rejected in response to preselected criteria which continues until a proposed list (1604) up to a predetermined lists size has been generated. It is a technical aid to assist with the manual building of quality links and not a tool for bulk link submission.