Directories have existed for a long time, in one format, or the other. The earliest directories where the various product lists that have been compiled by merchants all through human history. More recently we've had telephone directories, yellow pages style directories, web directories and now we have the dominant search engines. The advent of search engines has not removed the usefulness of directories, however, the role of directories in the search market has changed in response to the dominance of the search engines. Since a majority of people do a lot of their web searches via a search engine, individual directories are not going to deliver the levels of traffic.