You are right. I find it helpful to look at risk. Broadly speaking there are two types of risks when starting a startup: 1. Customer/market risk 2. Invention

You are right. I find it helpful to look at risk. Broadly speaking there are two types of risks when starting a startup: 1. Customer/market risk 2. Invention risk When invention risk >> customer risk (you can be certain there are customers, they have a need, you can satisfy the need), then a good idea will play a bigger role relative to execution (which still remains crucial). However, we tend to grossly under-estimate customer risk, hence the "ideas are cheap" warning.