I can only speak for Ireland which has been issuing these for more than a decade. In fact there are earlier experimental examples.
They are known here as Stamps on A Roll (SOAR). Each post office counter clerk has a computer/printer which issues the stamp in whatever denomination is required. Most smaller post offices no longer have commemorative stamps.
I have a collection of around 6,000 SOARs from about 1,000 different post offices. I have for example more than 50 issued in big city post offices and sometimes just one example from many small post offices.
A few years ago there were about 1,300 post offices. Now there are about 900 and I am still looking for SOARs from about 55 of them and in pre-Covid times, I travel around the country trying to pick up the missing stamps.
There is a theme to the SOARs. For a few years, Animals, Birds, Fish etc (usually 8 in a Roll)_. Then in 2016 we had Easter Rising (16 per roll) and since 2017 the theme has been Objects from Irish History (8 in a roll) and occasionally "popular" commemoratives are added)
There are I think 600 stamps in a roll arranged so that Stamp #1, 9, 17 have the same design and likewise #2, 10, 18 thru the roll.
There is not much value to them except that there is a small group of enthusiastic collectors, who are interested in the type face/font/colour might vary a little or the unusual denominations which can be anything from 1 cent to in my case €55.00.
For me it is the link to the post office itself.
There is a 14 digit code on every stamp.......the first four digits indicate where the stamp was issued (eg 1745 is Galway Post Office) and the fifth and sixth digit indicates the counter clerk 01, 02, 03 etc.
(I also have an interest in taking photographs of post offices).
But........are they stamps?
Well Gibbons certainly catalogued them but now (I am open to correction) list them seperately as "Machine Labels".
For what its worth, about three years ago a collector asked me to send him some Irish stamps and about 50% of the stamps I sent were SOARs and I wanted nothing in return but he was actually very angry to the point of rudeness that these were NOT stamps as they were not listed in Scotts.
There is really no real value to them.
But for me they ARE stamps. My main source is of course kiloware. I already have 6,000 in a collection and maybe another 3,000 unsorted.
This might helphttps://collectingstampsofireland.w....com/?s=SOAR