Find an associate Marketer

I have developed BackWatcher which is an app that alerts you when you slouch on PC. Yet I have to regularly bring enough people to try and buy BackWatcher. I need to work on Marketing: Content marketing, paid ads, and SEO. The issue is that it is not part of the job that I absolutely love. So I thought that a marketer could do this job and be paid for every sale. Are they marketers that work like that and where could I find them?