Tip: Take the stodgiest, oldest, slowest moving industry you can find. And build amazing software for it.

If every customer is using your product "correctly", you'll never learn anything interesting about what to do next.

You can look at the cost structure of an incumbent company and discover: where are they not going to be able to drop their prices... because that business model is fundamental to the existence of the company.

The only barrier to entry you can create is to consistently build a great product.

If you're in your early 20s and you're hanging out with a bunch of other people in their early 20s, nobody has a sense of the kinds of problems that real 'workers' run into every day. They're running into a completely different set of problems like 'what's the party going on right now that I should be going to?

Start with something simple and small, then expand over time. If people call it a 'toy' you're definitely onto something.

I think people are always able to achieve more than they think they can. While that’s cliche, I don’t know if managers think about that enough. You have to set your sights extremely high.