It's interesting that technology businesses didn't appear in any of the top grossing slots. I suspect this could be because they get lumped into professional / scientific.
As a percentage of the US GDP, small tech businesses aren't much of a blip. Just think of all of those real estate brokers and investors, day traders, hair salon owners, construction contractors that churn through 1M annually in revenue. Every small town across the US has a pile of millionaires like this.
Yeah, the only reason I even clicked on the link is because I just assumed the majority would be tech businesses, eg mobile app developers. Guess im guilty of living in a bit of a bubble.
Which technology business model scales that way? Back in the days you could probably keep a 1-person business with shareware or packaged software sales, today with SaaS model one would be pushed into hiring support people rather soon.