I run a few web directories, one of the directories, you either have to pay for inclusion or link back to my directory if you do not want to pay for inclusion. Its amazing how some silly people think they can full you into including their sites for free. There is a bug in the directory script which means if you enter the directory's own url as you link back destination, the directory sort of credit you to having link back to it. Other daft cheating techniques I discover includes providing the url of a third party that already linked to the directory as your link back url. Are you a directory owner, do you come across silly cheats like that too?