[bezout]

They’re legit - most of the times. Most of the times it’s cheaper to print on-demand if you don’t know how many copies you’re going to sell. For instance, OpenStax usually prints its books through Amazon.

I’m surprised hearing about big publishers such as Penguin using the on-demand service though. Maybe they use it to provide books which are out-of-print or which don’t sell a lot.

Given Amazon scale, I’d not be surprised if some of them are being sold by non copyright owners though.

[sandman1906]

These were all books that were quite recently published and I have seen all of them in bookshops.

In the past, I have received n>1 books which were sold by marketplace sellers but fulfilled by Amazon. Same inscription "Printed by Amazon", but these clearly had things wrong with them, like font issues.