totally agree with Randy, track the $%#@ out of everything. try to know which creative and which site stuff comes from at a minimum. I’ve sometimes use dozens of trackers for one program, to learn what works best.
Another thing, real simple: have plenty of links to the casino. if you have a page dedicated to a casino, make sure there is a link on the top, bottom and at least 1 every paragraph or two. I’ve increased performance by going from 2 or 3 links on a page to 5 or 6.