We all have great ideas. No one ever says, "I've got this terrible idea."

The Internet is such a tough marketplace because everyone is a click away from going back to a cat photo, or going back to whatever else they were doing. You have to win them over, and do it quickly, and do it by making something people actually want.

The best part of being an angel investor is seeing these kids coming up with companies that get way more traffic than Reddit had when we sold it. I think, 'Are you kidding me? They're just kids, and they've done so much.

Having that kind of endorsement and having Paul Graham's readership coming to your site and contributing to it and building the foundation of the community was just a really invaluable way to start Reddit.

You can throw - and we've seen plenty of these kinds of companies - millions of dollars in advertising for a website or a service, and in the end if it's not useful no one's going to use it.

Even if you have no interest in starting a company, having the experience of having ideas and doing them, that's muscle to exercise because that's what people are going to want to see. That's what makes you different.

Hundreds of these companies I've seen since the beginning stages - including Dropbox and Airbnb - one of them has actually been crushed by an incumbent. The Googles, the Twitters, the Facebooks, they might be someone to acquire you, which is not necessarily a bad position to be in.