I'm not exactly sure what you are referring to, not sure which agent you are talking too. But casinos, at the beginning, usually use email marketing to reach the potential gamblers. I have seen a few casinos to collect a big amount of email list at the beginning and use them to get some good deals.
Also, back in the days, twitch streamers were given big fund by casino which they must have to go through some requirements to be eligible to withdraw. Streamers have to use the fund to play live and attract gamblers.
Well, do you know this bitcointalk forum has a lot of high rollers too? Yeah, I know few of them. You have to run marketing campaign here to build up the reputation and offer some great benefits to attract high rollers from here. Feel free to PM me regarding any type of bitcointalk marketing campaign. I can help you with my years of experience in the related field.
I came across with streamers promoting gambling platforms such as lotteries and more. But the oldest way I guess, to attract players into your platform is thru referrals from people the owner has been connected to. Followed by social media platform posts and other procedures are internal agreement already. But if it is team you are looking for in 'affiliates' then you should post it in different platforms such as with this forum in order to catch potential players. Wait for their application and see for yourself what they could contribute on your planned business. Progressive development of the project itself is a huge factor.
In this era, there are indeed lots of gambling platforms that use affiliate services to carry out promotions for some of the games in them.
However, I think there is only a little interest from every gambler by streaming promotions carried out by affiliates. In fact, it is more effective as what you have said, namely with references and stories from the experiences of everyone who has used a particular gambling platform.
Maybe this is happening because now there are many gamblers who believe more in the experiences of other gamblers because it is more real and they really have experience playing on a gambling platform.
The gambling platform must consider properly if you want to use the services of an affiliate to carry out promotions.