I guess it would have been better to ask this thru PM but anyway the thread is here and i will answering it for the community.

You can add yourself your link with the "add your link" button.
As soon as 20 spots are reached, this button will automaticly disapperring.
The link-backs are randomly checked every 24 hours. If a link-back is still missing after 3 verifications, the spot is cleared and anyone else will be allowed to place his link.
That's working so.