What we're starting to see is that the best apps tend to be the simplest, the easiest to use and the fastest to use.

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.

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

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.

People can copy what you've done, but they can't copy what you still want to do.

I'm still a really shitty programmer, but I know enough to hack a prototype together.

Stop sketching and start building.