The ideal business co-founder has to be strong in distribution AND eliciting product feedback. This is why the “MBA types” and ex-McKinsey consultants fare so poorly - they’re used to companies spending loads of money to hear what they think. As an early-stage startup founder, nobody gives a shit about your product and no one wants to hear what you think. Your job is to identify where demand is highest in the market and then turn that demand into dollars. They also need to be excellent communicators who understand or at least appreciate how much goes into building products.

For those reasons, the best business cofounders in my experience, are former salespeople (for b2b startups), demand generation marketers (for b2c), and product managers.