Because, you know, resilience - if you think of it in terms of the Gold Rush, then you'd be pretty depressed right now because the last nugget of gold would be gone. But the good thing is, with innovation, there isn't a last nugget. Every new thing creates two new questions and two new opportunities.

I'm not saying that advertising is going away. But the balance is shifting. If today the successful recipe is to put 70 percent of your energy into shouting about your service and 30 percent into making it great, over the next 20 years I think that's going to invert.

If you double the number of experiments you do per year you're going to double your inventiveness.

Mediocre theoretical physicists make no progress. They spend all their time understanding other people's progress.

We've done price elasticity studies, and the answer is always that we should raise prices. We don't do that, because we believe -- and we have to take this as an article of faith -- that by keeping our prices very, very low, we earn trust with customers over time, and that that actually does maximize free cash flow over the long term.

People loved their horses, too. But you don't keep riding your horse to work just because you love it.

The three most important things in retail are location, location, location. The three most important things for our consumer business are technology, technology, technology.