Using the bankroll of a casino that should be normally there to support any winners, and basically a guarantee of sorts that you could play here, for marketing or any other thing to grow is not really a great idea. I also do not think that casinos should be doing it themselves at all, it sounds like a lot of work and with so much they have to deal with, I do not think that it would be a smart way to handle. Best thing is to focus on what you are doing and leave the marketing to an agency of sort, that way that agency would be able to make you more famous while you focus on the casino part of the deal. Not a bad idea at all.
I can’t comprehend the premise of your statement but since you are implying that casino marketing should be handle by 3rd party services then is only applicable to small company that can’t afford to pay a regular employee to do the marketing job. Casino is a business and not a development project so it’s normal that they will have there own marketing department because they need it on regular basis to attract new users to play in the casino. Hiring a 3rd party service will just a waste of resources since most of them charge an expensive fee.