Hi Bean, welcome to CAP. 
Bean wrote:
I am trying to decide between a sportsbook portal or a casino portal.I would go with whatever you know the most about. If you know more about online casinos, take that route. If you are familiar with sports, build a sportsbook portal.
I think most people on this forum would say that promoting casinos is more profitable than anything else. Apparently sports can be very rewarding as well if you know how to promote it correctly.