Greenwald, Sullivan and Yglesias got so big by starting blogs that they could sell to traditional publications. They are not monetizing an audience they acquired through larger institutions, but reclaiming one they created themselves. https://pllqt.it/lJGvqe 

That's from this CJR piece, btw:

https://www.cjr.org/special_report/substackerati.php

Maybe being a white dude advantages you in blogging, though I did all right. But my observation as someone who did it is that the qualities that make you a great blogger are much, much more specific.

Basically, absolutely voracious information consumption, very fast reaction time, the ability to write quickly and coherently, the ability to cover a broad range of topics, and the ability to keep it up over weeks, months, years. Most people--even most writers--just can't do it.

It wouldn't surprise me if that kind of very obsessive personality skews male, for example, though again, I did all right.

And that's what you need to be a good one (wo)man show. Though frankly, we were all overclocking and had to pull back eventually--by the time I moved to Bloomberg, I was in bad mental shape from years of 60-80 hour weeks without ever feeling like I could turn it off for 20 min.

Finally, and obviously, one major characteristic of the successful one (wo)man show is the ability to swim against a crowd.

Given that, it seems almost obvious that Substack would select on people who are not in tune with the dominant views of the establishment media.

And that the biggest audience numbers will come from folks who are not in tune with the establishment media in the ways most commonly found among infovores with disposable income for subscriptions.

(Okay, so I guess this wasn't obvious to everyone? If you're just saying stuff other folks are already saying, readers can get it elsewhere, and better edited)