You're going to pull out your phone and try to use whatever is the most appropriate app on your iPhone or your Android device. Yelp saw that very early on. And when we launched the mobile product, we saw immediate growth, and we were stunned.

If I see what you're up to on Facebook but I don't see your updates on Flickr, I'll still care about Facebook.

Being an entrepreneur is not about being in love with an idea, it's about being in love with running a company.

Right now, nearly all the apps on Facebook take a week to build. No more.

Having a highly homogeneous background, education, values, preferences, etc, in the very early team is better than not - cuts down on time-wasting arguments.

If you can work a brand successfully into the narrative of your product, then it's really cool. Then people actually take the brand up and say, 'My positive experience in your product is directly connected and influenced by this brand and that worked great.

PayPal once rejected a candidate who aced all the engineering tests because for fun, the guy said that he liked to play hoops. That single sentence lost him the job.