[sharpn]

I would flip the 'idea guy' & 'dev guy' percentages at least. An idea without development/execution is worth ~nothing, wheras the development of a good idea is valuable. Find the sucessful company that is closest to what you have in mind & see how they did it. Good luck!

[aberman]

Agree, but it depends on what you mean by "idea guy." Is this guy going to make sure that the lights stay on? Is he going to market the company, make the sales calls?

If he just came up with the idea, I would give him a few percentage points and say "thanks." If he is going to be the mastermind behind the execution and the driving force of the company, then I think he is tremendously more valuable, and his equity stake should reflect that.