Yes. Needs comparison to past years to be useful. Would also be helpful to compare books that came out in past year or few years to see how their sales trends. We also need to know what those books that are tracked are. Are they just in print titles? Or does it count 60 year old used biology textbooks for sale on Amazon no one wants? Or dated romance novels long past their prime? Because if those are included I'm not surprised they are struggling to sell 1000 copies. Even new books in niche academic fields can struggle to sell 1000 copies as the audience is so small.
I did mention Alexandre Dumas as a case study in a previous article. Here's a snippet:
"But there used to be another way. When Alexandre Dumas debuted The Count of Monte Cristo it was published as a feuilleton—a portion of the weekly newspaper devoted to fiction. From August 1844 to January 1846 his chapters were published in 18 installments for The Journal des Débats, a newspaper that went out to 9,000 to 10,000 paying subscribers in France—and readers were rapt by it.
In the forward to a 2004 translation of the book, the writer Luc Sante wrote: “The effect of the serials, which held vast audiences enthralled… is unlike any experience of reading we are likely to have known ourselves, maybe something like that of a particularly gripping television series. Day after day, at breakfast or at work or on the street, people talked of little else.”
It was basically “Game of Thrones.” Readers could not wait to get their hands on the next chapter and that bode very well for the writer who was not only paid by the newspaper in real-time for his work (by the word), but also grew the popularity of his work over the entirety of the time it was being published.
“The ‘Presse’ pays nearly 300 francs per day for feuilletons to Alexandre Dumas, George Sand, De Balzac, Frederic Soulé, Theophile Gautier, and Jules Sandeau,” Littell’s Little Age, Volume 10 wrote in 1846. “But what will the result be in 1848? That each of these personnages will have made from 32,000 to 64,000 francs per annum for two or three years for writing profitable trash of the color of the foulest mud in Paris?”
That “profitable trash” earned those writers an annual salary of between $202,107 to $404,213 in today’s dollars—and the obvious disdain of that Littell writer who, even then preferred the merits of a bound and published book. The same volume goes on to say that Dumas earned about 10,000 francs ($65,743 today) per installment when he was poached from The Presse by The Constitutionnel in 1845."
A comparison to the recent past and not the most successful French authors of the 19th century. For every Dumas making $200,000-$400,000 there was probably a hundred authors you've never heard of making $2000. And the market has changed so much since the mid-19th century as there is way more alternatives for people's time like movies, TV shows, video games, etc. with completely different distribution methods because of things like the internet enabling people to get content out for free.
You need to look back at the recent past and not just the most successful authors to see what the trends are. Is a random sampling of 100 authors from 2000 making more than those in 2019? Has the total number of books sold sharply declined?
Ever read Boswell's life of Samuel Johnson? Samuel Johnson was a poet, which was about as close as you could be to a rock star in terms of popular culture fame in the 18th century.