pg's article has been on my mind since yesterday. And I keep thinking how most jobs are in fact created by small and medium sized businesses. And startups really are just small businesses.
I like pg's reply above that a start-up is a SCALABLE small business. I'm still learning how to run a start-up. I've been running a small business for most of my working life.
That is a very good point. Ironically enough I was first hire at a biotechnology startup which turned out be a small business. It stayed in business but it failed to scale.