Profit share for content writers?

HI guys,

I am setting up a few niche websites and I've been more or less writing the content myself plus a bit of upwork content. I'm quite satisfied with it, but now I would like to encourage my writer to achieve better quality in their writing, so I thought about implementing a profit-share system.
Do any of you have experience doing this and so how have you set this up?
For info, it's writing amazon niche sites

Thanks for your input