Each casino has also to find its own way, because not all customer types will behave in the same manner. If you are going for the masses, you would need to provide a decent service at an affordable price, but if you are whale hunting the focus should be in help, service, usability,... the moment a whale perceives that there is commercial pressure or any sign of untrustworthiness the site is done.
Every casino has different behavior to attract the interest of gamblers, actually the focus for service, assistance, usability should be maximized for all active gamblers and not just for whale account hunting. But before advertising a gambling platform, make sure the casino has interesting games and fair games, customer service must be quick to respond when there are reports from users.