[daiidgo]

My friend and I recently encountered a similar situation -- we decided to put out a mobile game together, and we have a third friend that we knew was interested in joining the project. He could have given us lots of ideas, but little or no productivity.

My test for deciding if you want to bring an 'idea man' along is this:

Imagine that you and your friend -- the idea man -- work together at a nice day job. You both make a good salary. One day, your boss tells you that he wants to fire your friend (who wouldn't take a pay cut) unless you're willing to take a pay cut. Your have two choices: (1) take the pay cut, or (2) your friend gets fired. How big does that pay cut have to be before you let your friend get fired?

For me, it's less than $1,000/yr. I love my friends dearly, but I'm not going to pay a buddy just to hang out at work and keep me entertained.

Unless your friend's idea is going to make you wealthy enough that you no longer have to work, then you probably don't want to give him 5% of your company just to be your friend.