although the competition is very fierce in the gambling industry, but if the casino already has a lot of customers as well as one of the biggest casinos I don't think it is necessary to carry out promotions that spend too much money to attract the attention of new customers. because if the casino has become big, of course it will be enough to do advertisements, of course, people out there will already recognize that the casino is very big and trusted, so there is no doubt thinking about any risks.
except for the things you mentioned are done by small casinos that have to compete with casinos that are already big.
That should be doing by those casino owners but what I've noticed is the more the customer they have the bigger their promotion or advertisment to attract gambler in them . I thing youve seen also a lot of big time casino that still paying influencers or putting their names into big games or fight to attract new customer. I don't care if they still continue their promotion but they should take care of their current gambler like having perks or bonuses so that they will stay more in their platform
It is a part of their business model, they can't just sit calmly once they've got a certain amount of gamblers on their platform, they will surely strive to have more. Who doesn't like their business to grow even more even if it has grown pretty big already? If you are a business owner, your business is doing pretty well, will you stop wanting to make it earn more revenue for you? You wouldn't, and the same goes for casinos.
Take Stake.com as an example, they probably have millions of gamblers already registered with them, but they still strive to reach more and more people through advertisements, promotions, partnerships, and much more, because they want their casino to earn more revenue.