How should my users payments be setup?

Hi!

I created an Etsy style website where people can register and create their own store on my website. I have Paypal Chained Payments setup, so I can collect a 3.5% fee on the sale price of my users' products.

My question is, how should my users be setting up their payments to collect money, so that I will still get my 3.5%? Should they also be selecting Paypal Chained Payments in their store settings, or does it not matter?