Please answer LibraryThing related questions here (and on the other Help and FAQ pages). To ASK questions, however, please use Talk.
If you have come across an old or unusual book, you might be curious to know whether it is a valuable collectors' item. There's a good chance that you might be able to find out more about your book by tapping into the collective knowledge of LibraryThing members, but before you post a question on the Talk pages, there are some basic steps you can take yourself.
 First steps
- Look at WorldCat or national library catalogues to get an idea of the different editions of the book that exist
- Do a search on a secondhand book site on the web (e.g. for books in English, you could try ABE Books or the Antiquarian Booksellers' Association of America (ABAA)).
- Make sure that you compare the same edition and printing
- The condition of the book has a very big influence on the price. A 20th century book is likely to be worth a lot less if the dustjacket is missing or damaged, for instance. Booksellers use standardised terms for book condition
- Prices are strongly influenced by the scarcity of a particular edition and the current interest in that particular author/work/subject
- Remember that a dealer will pay you less for a book than the price they sell it for!
- Consult secondhand booksellers in your own area: they are the real experts
- For something really exotic, a search on Google or ABE Books can be a good way to find dealers who specialise in that type of book.
- Don't be too disappointed if it turns out to be worth very little. Not all old books are valuable, and you've still got a book to enjoy!
The lists below cover some of the things that often affect the market value of a book. They aren't absolute rules, though: in odd cases it may happen that a book is so rare that even a damaged copy is worth something, for instance.
 Typical positive indicators for value
- Early work by author who later became famous
- Highly "collectable" author or illustrator
- "Niche" interest (in some subject areas a classic reference book that has never been reprinted will sell for a ridiculous amount, if you find the right collector)
- Little or no visible damage or wear
- Original dustjacket
- "First printing"
- Special binding or printing (letterpress, hand-tooled leather, handmade paper, famous small press, hand-coloured illustrations, etc.)
- Ephemeral cheap edition where few copies are likely to have survived (but only if it's something interesting in itself, e.g. first magazine story by famous writer)
- Book that was suppressed or taken off the market (e.g. after a libel suit)
- Association copy - belonged to someone famous, linked to historical events, etc.
- Publication date before 1830 or so
 Typical negative indicators for value
- Late work by established author
- Mainstream "classic" published in huge editions (e.g. late-19th century editions of Dickens, Scott, Thackeray; most Bibles, schoolbooks, etc.)
- "27th printing" or similar
- Modern reprint
- Book club edition (although a few specialist book clubs actually add to the value of the book, e.g. the "Left Book Club" of the 1930s)
- Severe damage to pages or binding
 Seeking information on LibraryThing
- Try to post your question in the most appropriate group (e.g. Military History for a book on Napoleon, German LibraryThingers for a first edition of Goethe's Faust)
- Make the subject line as informative as possible, so that the right person will spot your post ("Seeking information about 1847 edition of Ivanhoe" NOT "Old book query")
- Describe your book as fully as possible in your post: give the full title and author, as on the title page, and the publisher and edition details