it is most likely the same owner some directory owners to kick start a new project they are working on will take the database from an existing one they own an buy and database from a another person. In 99% of the case its beneficial the existing submissions especially when the owner markets both sites. In some cases and I know this first had as I would do this some times. Link the databases with many different site different looks and what not but all the same content and market to the submitter that when they submit they will also be submitted to more then one directory. Its good for both parties as it encourages submissions and allows the submitter to get more links to their site. I hope this sheds some light.