With reference to <a href="http://kottke.org/09/09/the-zappos-movement">http://kottke.org/09/09/the-zappos-movement</a>
"What's gonna happen to Apple if something happens with Steve Jobs? That's why it needs to be about a movement, not about a person or even a specific company."
It could be risky when things rely on people for success. Coworking is a good example of a movement that is a success and is unlikely to fail because it doesn't rely on one single person to be pushing the concept.
Are there any other good example?