Printing Impressions (via The Passive Voice) sends this analysis of trends for 2019.

They show that, despite all our fears of a few years ago, print book sales continue to edge upwards. Maybe we are all in a sort of holding pattern, waiting till something better than the ebook comes along, or maybe there is really some brain circuit function which likes to turn a paper page or whatever. I do believe that book printing will become ever more digital and shorter run. I expect we’ll arrive eventually at a place where it looks weirdly quaint that there were ever warehouses filled with books waiting for people to want to buy them. If, by then, people still want a printed copy of a book it will be printed for them after they’ve paid for it. This seems a vastly superior business plan to the hit or miss method we’ve evolved, however skillful we’ve become at managing the odds. Just set it up and let it run.

See also Print on demand.