First principles totally get worked out in software.

37Signals did quantitative research to find out that for them, a girl smiling on their homepage for Basecamp totally works. Then 5,000 startups followed suit and the whole world is full of smiling girls on home pages.

But the principles behind that decision drive conversion for basecamp, not the girl.

It's one of the things that is most concerning to me about the Lean Startup. The idea that you can follow a series of steps to manufacture revenue without really understanding what those steps mean is hypnotizing.