19. An online electronic book service, comprising: one or more processors; and one or more non-transitory computer-readable storage media containing instructions that are executable by the one or more processors to perform actions comprising: receiving, from a device of an author and via a content ingestion service associated with a network, an electronic book; normalizing the electronic book by at least one of removing illustrations from the electronic book, removing extraneous characters from the electronic book, or converting characters of the electronic book to a single case; performing a first-pass comparison of metadata of the electronic book with metadata of different book title sets to identify one or more candidate title sets of which the electronic book may be a member; and based at least partly on a determination that the first-pass comparison identifies a partial match for multiple candidate title sets, performing a second-pass comparison of first body text of the electronic book with second body text of the multiple candidate title sets to determine that the electronic book is a member of any of the multiple candidate title sets.
23. The online electronic book service of claim 19 , wherein the second-pass comparison comprises comparing edit distances between the electronic book and the multiple candidate title sets.