I'll give you 6% for my "startup" for 950 hours of work. <B>Jokes aside, the MBA way of thinking is as follows:</B> 1) What has he already provided for the oth

I'll give you 6% for my "startup" for 950 hours of work. <B>Jokes aside, the MBA way of thinking is as follows:</B> 1) What has he already provided for the other 95% (customers, revenue etc)? 2) What is the chance that this startup will be successful and yield a big enough return on your investment? Here is the math: Amount of cash the 5% will yield on exit needs to exceed the Salary for $1000 hours of work multiplied by (1/(probability of success). If the two above make sense, then you need to consider the opportunity cost of spending the 1000 hours on his project over another one. <b> Other way of looking at it:</B> Do you really like working with the guy? Is he brilliant, a good team and your not sure where it will end up? If so, maybe it is worth negotiating either some up front cash or a bigger percentage if the math doesn't work and just go for it. Worst case scenario you loose some opportunity to work at another startup and you get some business experience and programming experience you wouldn't have otherwise.