When the American newspaper was in its prime, there was a rule of thumb for newsroom size: one staff member for every 1,000 print copies sold. What would its equivalent be today?

The implosion of print advertising has transformed the economics of journalism, from the go-it-alone newsletter writer on Substack to subscription-first publishers such as the New York Times or Washington Post. The internet brought huge potential audiences.

But, strangely enough, the modern journalist-to-reader ratio for subscription news might not be so different from the money-spinning, ad-reliant US newspapers of old. At $10 a month, 1,000 or 2,000 paying subscribers per staffer is enough to earn a decent living for a Substack writer, and potentially to turn a profit in a digital newsroom.