Building a product is easy. But building the company that builds the product is hard.

Don't let other people distract what you're doing. There's always haters.

Don't let people tell you your ideas won't work. If you're passionate about an idea that's stuck in your head, find a way to build it so you can prove to yourself that it doesn't work.

Hire the best people you can find. This was kind of easy in the early days of foursquare - we hired our friends who were really passionate about the stuff they were building. We have a superstar team not just because their resumes are so strong, but because they've been passionate, thinking about and tinkering in this space forever. Those are the people you want to surround yourself with.

Build something that fixes something people are having a problem with, and you're lined up for great things.

I keep a notebook in my pocket, and I write down all the stuff we could ever do with Foursquare.

Don't let people tell you your ideas won't work.