Peter Thiel on the question he asks every startup founder he invests in

Whenever I have a few people who are in the process of starting a company, I ask why will the 20th talented person join your company? When they can get paid way more at Google, they will have to work way less hard at Google. It will look better on their resume to go to Google. Why in the world would they ever join your company? The monetary answer is generally not a good one. That works in a few rare cases. But chances are that you won't at employee 20 have a business that's so robust and doing so well financially that it's a no brainer to people to join it. Yeah, the equity might be worth more, but it gets diluted. The 20th person doesn't get that much equity as a percentage. And so what I the answers that I think work are that somehow you are in a really unique business. This is the only place in the world where you can work on this incredibly important problem. And that's the kind of answer you want to give. It has to, on some dimension be a really important problem that at least some people think is the most important problem in the world. Those are the kinds of businesses that are unique when they work, they end up being leaders in their respective markets. And that's sort of, I think, the general formula that works. On the other hand, if you do something where you have 20 other people doing it, even though it might seem easy to start, it's extremely hard to build out.