[jasode]

>substantial advertising market [...] thriving advertising industry, [...]

Whenever I see that "newspapers were always ad supported", I take it to mean the mainstream press and not the early financial papers that went to subscribers on Wall Street or the political news that was paid for by wealthy patrons. (Mainstream == readership of working class people.)

The "penny press" in the 1830s[1] is an example of lowering the price from 6 pennies to 1 which enabled a wider readership. Advertising made those economics of mainstream publishing possible 30 years before Holt's focus on an "advertising industry". I understand Holt's logic but to me, the idea of advertising quantity is not relevant to how the earlier advertising created the financial support for mainstream newspapers.

[1]https://en.wikipedia.org/wiki/Penny_press

[dredmorbius]

Holt addresses this, the advertising vs. subscriptions rates dynamic and how that affects circulation, the first fully free advertising circulars, and the 30x growth of publishing 1850 - 1905. That's 3000% growth, mind, not 30%.