Most casino affiliates start out building banner farms, and generally don’t make money until they have a few different banner farms built and they can start linking them together.
Write good, targeted content and you will see returns more quickly. Look around at different sites and you will see the majority of them are still banner farms. Go the opposite direction- write good content and monetize through text affiliate links rather than banners. For the most part they are more effective in addition to not looking trashy.