Of course we have a mechanism to filter books: publishers. They

Now ebooks and on-demand printing allow you to "publish" books without going through the quality filter of a publisher. But you won't get into a book store that way, and anybody talking about the trouble of archiving those better already have an archive of the low hanging fruit of the same category: fanfiction.org and friends (and I don't mean this derogatory, there are great stories in there)