These arrangements require strong people willing to be rigorously honest with each other. Too often I have seen "Mr. Brains" partner up with "Mr. Wallet." Soo

These arrangements require strong people willing to be rigorously honest with each other. Too often I have seen "Mr. Brains" partner up with "Mr. Wallet." Sooner or later Mr. Brains thinks the business would be nowhere without his ideas. The business would have launched successfully with a nickel of capital. Mr. Wallet sooner or later thinks the business was self-ordained to succeed and even a monkey could have launched it. His capital was the critical ingredient and you could have been replaced by minimum wage high school kids. In this situation -- far more than any other -- you need extremely good legal documentation. (Define this as a buy-sell agreement, with extremely clear mechanisms for how to deal with the situation where there is a disagreement and one of you has to leave.) Otherwise you, as the person with the thinner wallet, will lose if things come to push. In legal battles the win usually goes to the person who has the financial staying power. From your brief description of the situation, you are facing an odd hybrid of getting a co-founder as well as getting an investor. Analyze the situation from both perspectives. In my experience, things seem to work better when business partners face approximately equal risks and expect approximately equal (maybe I should say proportional) rewards. Otherwise, the weaker one is a disguised at-will employee with a contingent, equity-based salary.