Hey! I just went through the exact same thing for https://Sunboxlabs.com - shareasale et al have high up-fronts or monthlies and their own integration cost. I know people are gonna tell me it’s not worth half a day of engineering/debugging, but this is what I did for a roll-your-own affiliate mvp: write a ten line script to check the search params and set them as local storage or cookie. On checkout pass that cookie through to PayPal. Done!

Obviously I’m not getting the exposure of shareasale, impact, etc from being on their platform, but I can still sign up for them once I’ve validated that affiliate works for high ticket item hardware.