Keys2Traffic is a free email advertising platform created by Maryanne Myers. Basically, it's a regular credit-based safelist, but with some gamification, for example, credits are called "golden keys".
You receive 50 golden keys after registration. Each one allows you to email one member of the website once. If you need more keys, you can earn them by reading emails from other members (you should turn on this option into your account settings, it's turned off by default) or buy a paid membership. This membership, bought once, will give you free keys monthly without any requirements or obligations.
Now about their affiliate program. If you refer a person and they buy a "Key basket 1" membership, you receive $15. If they buy a "Key basket 2", you receive $25. Payout methods are CashApp, Bitcoin, Skrill, Zelle, Wise, Venmo and Amazon gift cards.
More info on program's website: https://keys2traffic.com/yarvinen
