A "professional" salesperson.

As an independent professional, you may call yourself an entrepreneur, a freelancer, a bootstrapper, an impresario, a writer, a creative, an artist or whatnot.

These are all good, but if you are not on a salary, you are now a salesperson. It's your choice though, whether you want to be a professional at it or not.

Yes, you may get to be the CEO some of the time, but if no one is taking the responsibility for making sales happen, the company is going to be in trouble.