You make a fair point, and I also do appreciate the definition used by Sam in his post, which was (the site is now down) about network effects compounding the bigger you get, and creative a positive feedback loop. I buy that definition, sure, and I get your comment. However, what I take issue with is funneling tons of smart minds into a quest for green-field or blue-ocean opportunities. There are tons of huge opportunities in existing businesses. I guess I don't understand how we got from "disruption" to "find a business with no competition."