If you know what you want, you use Google. But if you don't know what you want, and you want to be surprised and find something you didn't expect, we want you come to StumbleUpon. Really, that idea of being a discovery engine versus a search engine.
A lot of productivity is capturing ideas. I use a wiki - it's more valuable than e-mail for running a company - and I have a page for every person with whom I interact frequently.
I'm interested in sites that help people find information and filter what's available. The Internet is so big that no one can stay on top of everything.
Every time I make a mistake with a company, I write it out and try to figure out why it happened.
I definitely see a correlation between how many things a company gets right and how fast a company grows.
The way the Facebook network is set up, it's not as suitable for content discovery. Twitter is better, but there are too many over-sharers. Also, on Twitter and Facebook, everything comes from people you know. On StumbleUpon, it comes from people that you don't necessarily know but share your interests.
If the founders of a start-up are considering selling it, I'd advise them to consider the synergies. Could the buyer give you access to something you don't have now, like a certain technology? Would it make your life easier? Are you looking for a change? Things will change, so you have to be ready for that.
I like to say StumbleUpon provides a personal tour of the Internet. The responses are more targeted to your interests than they would be with a regular search engine. If you choose a topic on our site that you're interested in, such as art, Web sites related to art appear, as if you're leafing through an art magazine.