You can't get married to any one particular plan. That is the biggest lesson I learned at PayPal.

The very first company I started failed with a great bang. The second one failed a little bit less, but still failed. The third one, you know, proper failed, but it was kind of okay. I recovered quickly. Number four almost didn't fail. It still didn't really feel great, but it did okay. Number five was PayPal.

The single most important top-level trend is the shift to mobile.

If you're building a social product, you're still living in the last century if your product doesn't work on Facebook.

If we compare the two, Facebook is currently a superior place to market a product like Slide. Twitter is more like a general distribution agent. It's like broadcast radio.

I've been developing mobile for years before anybody else really thought it was that important.

Mobile is the perfect example of what is enabling economic growth in the technology sector.