The problem with Coinbase and Binance is that most people have already signed up … and their KYC policies prevent users from creating multiple accounts.
As a result, you have to attract brand new users via your affiliate link.
There are crypto trading programs which you can promote, but it surprises me that popular YouTubers are basically pushing merchandise like hoodies, t-shirts and stuff.
So many scams also … the industry is full of scammers who don’t pay, even once you earned your commissions.