
The book needs to be not copyrightable at the moment, then you need to have a copy, then you need to put work into scanning and OCRing it, then to place it in somewhere accessible. It’s a pretty narrow window. Some books that get published now get no digital release or it’s put behind a heavy price tag.

At the time they were pretty useless though. Moreso than Meta’s ones. Some hipsters from Silicon Valley bought it following the fad but then found they can’t do anything with it.