He has content and traffic. Fine. But unless this is a media website or about branding, the actual "secret sauce" will be the functionality (yet to be coded). I

He has content and traffic. Fine. But unless this is a media website or about branding, the actual "secret sauce" will be the functionality (yet to be coded). In that sense, your work will determine 100% the success of the company. As such, 5% doesn't sound fair to me. Also, if after 5 years, he's gotten no revenue, you're number one question as a potential share holder is: Why is this? and How will this change with my involvement?