It all depends on which casino program you decide to push, you can get special deals has long has your site has good rankings. For example in january i got paid $6000 for 30 players regardless of weather the player deposited $10 or $100. If your site is getting plenty of traffic then you can ask for a flat rate fee lets say for example $10000 for 1 months exposure on your site. Has long has you can send at least 24 to 30 players a month then the casino program or at least the ones i work with will be happy to renew month after month.
If your site isn’t getting much traffic at the moment then your probaly best to go with revenue share untill your traffic increases. Deciding which casino to promote on revenue share will be pretty much trial and error has what casino converts on your site might not convert on my site and vi versa.