Facebook, now a $100 billion company, became hugely popular with normal people first, and then the coastal tech elite.
Pinterest is currently following the same pattern, though mostly among women. It is the second fastest growing Web site ever.
What trait do Facebook and Pinterest have in common that other entrepreneurs could copy?
Both take an analog, off-line activity people were already doing before their product existed – before the Internet existed, actually – and made it 1,000X easier and more fun to do.