Looking for freelancer to boost my sales/promote

Hello,
looking for a freelancer marketer who is willing to help boost sales of my new website related to quite a competitive niche. Thing is, I can offer only a small upfront payment but your reward will comission-based. So if we make a sale, just as an example, third of it (35%) is yours. I am looking for more long-term cooperation, so as we grow and scale, we can rise the prices etc. This is not owner – freelancer relation, you'll be my full business partner, so the share will be equal…

Looking for freelancer to boost my sales/promote