Having affiliates market for you is awesome. They refer customres to you, you both make money, and the customer gets a product that really helps them in their lives. It's easy for your affiliate, it's easy for you, and you only pay a commission on the sales you actually make. Much better than paid advertising where you pay per click, no matter whether you make a sale or not.
Some great affiliates also have networks of other great affiliates, and they can help you by making introductions, so you get even more affiliates referring customers to you.
But how does that affilitae benefit from that? Until now, they haven't.
But now they can have affiliates register using their own personal affiliate registration link, and they'll get a cut of the commission. How much is up to you to decide, but 5% is pretty typical.
You also get to decide whether that comes out of the sub-affiliates' commission, or it comes out of your take-home amount. So if affiliates normally get 30%, and the super-affiliate gets 5%, does that become 25% to the sub-affiliate and 5% to the super affiliate, and 70% to you, or 30% to the sub-affiliate and 5% to the super-affilate, and 65% to you. It's up to you how you want to do it.
To get started, go to your affiliate program and click "Edit affiliate program", then check the box that says "Use a 2-tiered affiliate system" and set the settings how you like them.
After that, each affiliate will see a link that they can give out for other affiilates to register, and they'll automatically be registered to that super-affiliate, and they'll get their cut of the sale.