Strictly speaking you are breaking the rules.One advertisement maybe forgiven, but really you are getting free advertising. So only do it once!
To advertise on this,or any other site, you have to register with an Agency, or with something like Google Adword. You will see the legitimate adverts on the left hand side of the page.
So, as Petrarca has said,you may advertise,as a Posting, once! Do it twice, and you will be gagged.