Are there any ways I can offer affiliate partnerships on this basis...
Free to me (reason: I am extremely low-volume on sales).
Offers a percent of profit, rather than of revenue (reason: I incur costs and taxes that fluctuate and are unpredictable).
I'm Richard - CRO Expert at PageFly Landing Page Builder. Welcome to Shopify Community!
In this case, you could refer to the app UpPromote: Affiliate Marketing by Secomapp. I see that they offer FREE plan as well.
I hope my recommendation would be helpful to you.
Best of luck!
I hope you are doing well! Sachin here, from the AiTrillion-an All-in-one Marketing Platform on Shopify.
If you need help with a setup you can email at email@example.com. AiTrillion provides free app setup.
P.S- Free Plan Available