As a dev I entertain this idea on 4 criteria - 1. You are a veteran in the target industry. 2. You have connections and you are well-liked. 3. You can sell to t

As a dev I entertain this idea on 4 criteria - 1. You are a veteran in the target industry. 2. You have connections and you are well-liked. 3. You can sell to those people. 4. There is a mutual trust and respect between us. If you know the industry inside out and you are willing to sell, I would have no problem to partner up. But usually those who are successful in an industry rarely have enough time to invest in a startup. People I want to partner up with are so busy managing their business, client and family, they will just end up having a custom software made with their money and try to sell that.