I'm a big big fan of the "1000 true fans" concept as applied here. It's not for everyone but.... who knows? If you are persistent and passionate...
Note: this isn’t about strict numbers. 1,000 true fans paying 10 bucks a month might be enough. The same paying $2 a month? Doesn’t pay the bills of a family.
I like the concept as well, because it seems a lot more approachable than trying to build a unicorn, but what if only the top 0,1% really get 1,000+ true fans? Still a power law.
The rule of thumb for email subscriber to paying customer is actually closer to 1% (compared to your 10%) which just means it's that much harder. I don't think there is a rule of thumb for "true fan" conversion, where it might be as high as 50% for something like Tesla and 1% for something like Comcast.
Really? Maybe not every family (and definitely not in the Bay Area), but those numbers work out to $120-240K/year, with no requirement on where you live.
EDIT: I can't be trusted with mental math. Leaving the above unchanged, but it's answering a comment that used different numbers that never actually existed. The correct numbers are $24-120K/year, which is obviously a very different discussion about feasibility.
This may hold true for music, given a long enough time. Not so much with a newsletter which is limited by the language (at best two), and has a quite limited shelf life.
So "1000 true fans" is already a big filter.
In fact, e.g. for 2017, 99% of the 377 billion streams were from the top 10% of 2017’s most-streamed tracks alone. Less than 1% of streams accounted for all other music.