I've been freelancing websites on the side for a while now, and think I am ready to take on more work. My friend who is in sales wanted to help sell websites for me. What is a typical percentage for someone filling this role? He basically was going to serve as someone who knocks on doors (not literally), and serves as a project manager for these websites (following up with clients, organizing info etc).

I know this rate is subjective, but I don't even have a good starting point to work from...

Thanks!!