Jason Lemkin, managing director of Storm Ventures and SaaStr.com, spelled it all out, in no uncertain terms. Some key tidbits:

1. You will be the first VP of sales for your startup, until you make a few hires to help with the work load.
2. Don’t hire a VP of sales too early –  ideally after you achieve $1/$1.5 million in revenue, and you will need this person along with two reps you hired.
3. Reps can only have a negative impact on your company’s finances if they don’t perform.
4. The Sales VP’s main job should be to build a great team, and recruiting good hires takes time.
Great VPs will raise revenue per lead, closing deals smartly.
5. Make the hire once a repeatable process is established, because a bad hire can be worse than no hire at all.