It's a really paradoxical thing. We want to think big, but start small. And then scale fast. People think about trying to build the next Facebook as trying to start where Facebook is today, as a major global presence.

You've got to think about big things while you're doing small things, so that all the small things go in the right direction.

No one is too small for anything. You just have to think big!

For me, the winning strategy in any start-up business is, 'Think big but start small.'

The big success stories - Facebook, Zynga and Twitter - are leading to investing in ideas on a napkin, because no one wants to miss out on the next big thing.

In my first start-up, I had an initial advertising budget of $5 per day total. That would buy us 100 clicks per day. At $5 per day, marketing people scoffed and said that is too small to matter. But if you think about it, to an engineer, 100 real humans everyday giving your product a try means you can really start improving.