Successful authors recognize that readers prefer to buy books with well written
and organized indexes. A good index adds "perceived value" to a book which in
turn increases book sales.
An index written to generally accepted indexing standards performs flawlessly, and
provides quick efficient access to information. The reader finds what he/she is looking
for and doesn't give the index a second thought. However, if the index is poorly
written, the reader becomes frustrated and will very likely move on to the next book.
Non-fiction books published without an index are not likely to be taken seriously by
readers, reviewers or librarians.