If I see that an affiliate program contacting me is a well-known and have good reputation in online gambling biz then I'll tell them that I add their brands to my plans for the next month, and their products will be reviewed and added to my site.
If I see that an affiliate program is unknown and have predatory T&Cs I'll tell them "No", of course, after such emails they start changing their T&Cs, for example, they remove "a minimum player rule", "change the minimum payment from $1000 to $100" and etc. After that they again contact me and again offer me to join, and of course, I say to them "No", because they are unknown and had predatory T&Cs, it's enough for me to say "No".
I have a lot of other ways of working with new affiliate programs, and it depends on the current situation.
Regarding $1,000 'retainer' of other amount, sometimes I ask affiliate programs to pay me for adding their brands to my site, and it again depends on the situation. Usually I'm very busy, and I make my plan for the next month in advance, and I prefer not to change it. But when an affiliate program wants me to add their brands to my site as soon as possible, I'll ask them to pay me for that. Some of them agree, some of them don't agree. It doesn't matter to me