Since much of the discussion here is revolving around what journalism is or isn't or when its heyday was, or what its economic foundations were, I thought I'd share some of the research I've been making into the history and background.
The term "journalism" itself dates from 1821.
http://www.etymonline.com/index.php?term=journalism
The US mass newspaper industry dates from the mid-1800s. Yes, there were earlier instances of things called "newspapers", and some advertisements, and some magazines, and other means of distributing news. But none of these really jive with our current use of the terms.
Specific advances in economics and technology in particular drove the change. From the absolutely fascinating (and, warning: massive time-sink) History of Information:
Economic & Technological Advances Spur the Development of Newspapers in the U.S.
(Circa 1800 – 1840)
http://historyofinformation.com/expanded.php?id=4792
Dates and qualifications are numerous and various, and there's plenty of room for argument. But if the discussion is of a daily publication distributed on the events of the day, widely read through the general population, and supported through commercial means, then you require 1) high-speed communications (telegraph, phone, or better), 2) high-speed presses (steam, diesel, or electric drive), 3) iron or steel framed presses (for speed and durability), 4) distribution (intra- or inter-city, meaning posts or better), 5) manufacturing and distribution capable of supporting advertising-promoted wares, and the real biggie, 6) general literacy within the population.
None of these existed prior to 1800. Generally, full flourishing didn't occur until roughly 1880, though the pieces were falling in place before then.
For much of the 19th century, newspapers were largely party-run, not-for-profit. Prior to 1800, newspapers as we know them really didn't exist. Pamphlets were the typical mechanism through about 1500. Before that, "mass media" usually meant "the Church", in Europe.
Hamilton Holt, a magazine publisher himself, gave a view of the commercial periodicals business in a 1909 lecture at the University of California, "Commercialism and Journalism". He leads with a statistical account of the growth of the publishing industry from 1850 to 1905, in revenues, circulation, publications, and more. Much of the piece looks at the influence of advertising-driven interests on what is covered in publications.
https://archive.org/details/commercialismjou00holtuoft
From Robert J. Gordon's The Rise and Fall of American Growth, an interesting statistic: the fall in newspaper subscriptions, measured in terms of subscriptions per household, has fallen at a nearly constant rate since the 1950s. The decline in newspaper journalism is a very long-term secular trend.
I'd also strongly recommend David Simon's "The Audacity of Despair", a 70 minute lecture at UC Berkeley. Warning: Simon is not a great speaker, and yes, this is long, but he makes some exceptionally good and cogent points.
https://m.youtube.com/watch?v=nRt46W3k-qw
Another useful resource is "Introduction to Communication Science" by MOOC ICS, a fast-paced but solid introduction to the field of communication science. The segments are brief but well-produced and relevant.
Elizabeth Eisenstein, The Printing Press as an Agent of Change is very strongly recommended on this topic.
http://www.worldcat.org/title/printing-press-as-an-agent-of-...
Her paper, "Some Conjectures about the Impace of Printing on Western Society and Thought: A Preliminary Report" (1968) covers much of the ground though in far less detail, it's a good overview to her subsequent life's work.
http://www.journals.uchicago.edu/doi/abs/10.1086/240164?jour... (Full text available via http://sci-hub.cc)
The History of Information has a topic covering journalism including to earlier dates. The premise Lauren makes of a commercial practice of journalism prior to 1800 is very poorly supported. There's some argument which can be tenuously made to claims of "newspapers" in the 1700s or 1600s, but they're a long cry from what we see today, and were not generally read.
http://historyofinformation.com/expanded.php?category=News+M...