Since it is too late, I am happy to explain the thoughts in the above comment. I studied this area of economics from formal sources as well as having exposure to startups.
To summarize. One might think that if, say, a guy might be able to get a pizzeria off the ground, and it's 50/50, if it works he'll make a business with an enterprise value of $20,000 using his $5,000 investment, that's our assumption -- then if he wants to raise his sights and make the same investment, but this time is targeting $200,000 - his chances of success drop to 5%. And if he targets $2M then they drop to 0.5%. And if he targets $200M then they drop to $0.005%. If he targets $2B then they drop to $0.0005%. And if he targets $20B then it drops to $0.00005%. If he targtes $200B then it drops to 0.000005%
But 0.000005% is 1 in 20,000,000. There are 318 million people in America, so by those odds, the number of people in America who are capable of building a $200 billion business is exactly 15.
Yet there are more than 15 American companies that had those kinds of valuations in the past couple of years; Apple alone would account for 3 of them.
So with these kinds of large-scale successes, the risk-reward equation clearly doesn't actually work. And this ignores all of the home-run hits short of $200 billion. Clearly, risk does not increase at the same rate that reward does.
The risk-reward trade-off is just not a model that you can successfully employ when it comes to startups.
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Secondly (this is not directly related to the above) the world is super-connected. There is 0 chance that if I find a pizzeria run by some guy in the city with 1 location as a small business, that 14 months from now it will have 50 locations that he personally operates. But if you find some guy with 2,000 downloads today from the Google Play store, there is no reason this same guy can't make something else and get 200,000 downloads. That is a factor of 100.
So the whole IDEA of a "small-business" just doesn't apply to online startup-like economies. The only question is whether the guy who made a niche app with 2,000 users is even interested in trying to use his same skills making something innovative and new, which he gets good press for, but which addresses the whole global smartphone audience.
The thing that makes it a startup is this hyper-growth component, like whether he's trying to roll out at that scale.
If someone doesn't understand either of the two (quite distinct) arguments above, or has any type of comments or rebuttal, I can follow up. Thanks for your time.