Books, like everything else, have their own natural lifespans. Publishers of original material thought likely to be popular may choose to invest in a larger print run, which ensures more surviving copies. Conversely, marginal works might only merit a small initial outlay, with any reprint contingent on successful sales figures.
These can be significantly affected by capricious reviews; many a worthwhile book has been torpedoed by a few unfortunate published remarks. Likewise, local-interest books produced in minority languages in relatively small, predominantly monolingual target markets – such as for English-reading audiences in Hong Kong, Thailand, Taiwan and Japan – result in even smaller print runs.
Unless serious bibliophiles in a particular subject areas assiduously collect whatever newly appears, many titles sink without trace, becoming largely forgotten reference-library fossils. Eventually, some titles become of sufficient historical, cultural or literary interest to merit a full reprint, and find a new life.