I persume it would be an exlusive deal where you will only market there properties and receive either a fixed amount per month or CPA+Rev share. These kinds of deals can work quite well and i have done them in the past with good results, dont settle for just a fixed amount if you can send quite a few players.
Push for the most they are willing to offer, when i did media sells with Intercasino and another casino they were paying $800 per player but i doubt you would get that now and you really have to have an established portal that can send lots of players.