Jason M. Lemkin argues the optimal time to hire a VP of Sales is after a startup has two scaled, quota-hitting sales reps. At that point there is a repeatable sales engine for a VP to replicate and scale (from a few reps to hundreds). Hiring a head of sales earlier is usually ineffective (rare—about 5%—success).
Chapters
If you can the right the perfect time to hire the VP of sales is when you have two scaled reps. Ideally take founder led sales to two reps that can hit quota. When you have two reps, you have the beginning of an engine. You have something that someone that has sales experience can replicate. Okay, so if you have two reps hitting quota, you can go out and fire your first stretch VP of sales and her or his job will be to take you from three to 300. Once they have two, if they're smart enough to understand the pattern, close some deals themselves, listen and learn to these two. The good ones will listen and learn, the mediocre ones will disregard them. The two ones will see it's a blessing and they will find two others like them. And then the next two will be a little less like them. And the next two as you develop a playbook and get some heterogeneity and some diversity. But if you hire a head of sales before two reps, maybe 5% of the time it works out there's nothing for them to build on.