On one hand, they are committed, know each others' strengths and love taking their work home with them. On the other, that's a whole lot of extra pressure each on two already challenging relationships (cofounders and spouses). Non-married cofounders can break up and hey, one assumes that marriages are entered into for the long haul. How big a deal is this?

My theory is that married cofounders will be seen as a problem if the marriage is considered to be augmenting an existing problem that the prospective investor sees. If the investor already is perceiving a start-up to be too niche or narrow in scope, a pair of married co-founders could further serve to convine that investor that it's a pet project rather than a real company.

I agree with both of you, but here is the difference. I will liken it to the fact that I am divorced and co-parent my children. My start-up is my child that I raise and nurture. Even if I break up with my co-founder I will move heaven and earth to make sure that start-up grows up. Here is a link I found from last AUgust on the apprehension of VCs to invest in a co-founded startup finance.fortune.cnn.com. Thanks for the invite to the conversation.

Is there any hard data to back up the theory that married co-founders are more of a risk? I used to drive trucks for a living (I know!) and in trucking, husband and wife teams are preferred because they are efficient and have the same financial end in mind. Even as part of a team, unmarried, I was at a disadvantage for gigs. Married teams were seen as having it all together. I don't know why this favoritism doesn't translate to tech unless there is hard evidence to the contrary.

I have not seen hard data. I suspect in the SMB space, which is self funded and not VC funded, you see many married teams. In the history of the world there are examples of big wins and fights over business assets. I think if you can convince an investor that you have it together through your plan then you have an ear, but some people will always judge or be risk adverse.