To confirm: we have many users who use CC as a catalog using the technique that eschwartz described.
One use case is that someone buys both electronic and physical books, reads the ebooks on some dedicated reader (no CC), and wants to have an easily-searchable catalog on a phone (or something) that is consulted before buying a book. One user said that she kept re-buying the same books and wanted to put a stop to that.
Another use case is someone who reads on a dedicated reader that doesn't have adequate metadata search/organization mechanisms but is otherwise a satisfactory device. The person would use CC to find the desired book then open that book in the reader.