I prefer to invest in a company that's going after a small but rapidly growing market than a big but slow growing one.

You want an idea that not many other people are working on, and it's okay if it doesn't sound big at first.

AirBnB spent 5 months interviewing their first employee, before they hired someone and in their first year, they only hired 2 people.

If you compromise in the first five, ten hires it might kill the company.

If someone is getting every decision wrong, that's when you need to act, and at that point it'll be painfully aware to everyone.

In YC's case, the number one cause of early death for startups is cofounder blowups.

If you don't love and believe in what you're building, you're likely to give up at some point along the way.