While an unabridged audio book provides a reader with the full content of a book, an abridged audio book contains only excerpts. While an unabridged book is ideal for students attempting to complete assigned readings, an abridgement suits the needs of recreational readers who wish to avoid boring details and concentrate on a book's most compelling passages.
Unabridged audio books typically cost more than abridged copies. For example, while an abridged copy of "The Grapes of Wrath," released in 1995, originally retailed for $88.43, a 1998 unabridged release of the same book originally retailed for $239.44. As of April 2010, used copies of each of these releases were available for sale online for about $25.00 and $70.00, respectively.
Requiring only a relatively minor investment of time and energy, abridged audio books permit listeners to casually sample the contents. With an unabridged audio book, a listener can thoroughly absorb the contents of a book, leaving no word neglected. Neither version requires people to strain their eyes reading printed text.
Before the advent of computer technology, books on audio were chiefly marketed in audio cassette and compact disc formats. As these two formats have gradually ceded popularity to digital copies available for download from the Internet, publishers of audio books are establishing an online presence by maintaining virtual audio book rental services.
In his article "Can You Say 'War and Peace'? Great! It'll Only Take 23 Days," Washington Post contributor David Segal observes that "downloadable books make it possible to store a spoken-word rendering of a big fat tome on an iPod, eliminating the need to stuff 25 CDs in a glove compartment."
Following a business model pioneered by the online movie rental company Netflix, these audio book rental services allow customers to pay a flat fee for monthly rentals that is scalable according to how many books they wish to borrow at once.
Because they are costly to purchase and difficult for booksellers to allocate sufficient shelf space to display, listeners to unabridged audio books frequently borrow them from libraries. Recognizing this unique market, publishers are motivated to work with library staff to address quality issues.