I think 1 business geek + 1 hacker has better chance of success than 2 business hacker. Paypal was founded on a similar model. However, what often happens is one partner tends to underestimate the hacker - either the business geek finds the hacker useless or vice versa. I guess some level of understanding and respect is an important element in any partnership.
Underestimating "the other's value" is a sign of immaturity and lack of experience. The more I learn about life, the more I appreciate everyone around me more. I'm sure lots of people underestimate civil engineers, car designers, pilots, surgeons, micro-biologists, etc. because life is complex and we have no idea how challenging people's contributions are and how they affect us. Having said that, IMHO it's usually hackers who underestimate everyone else's contributions ... until they get to the point where nobody's signing up for their "thing" or they have people sign up, but nobody's willing to pay them for it. THEN the value of business models, marketing expertise, sales techniques, etc. come into perspective, when they realize all the tweaking in the world doesn't necessarily translate into the handing over of the cash from paying customers.