photo by LDyck
Why prepare a list (one to three) of published books that are similar to your manuscript? Why do a book comp?
-it's an abbreviated way to present your book to an editor or an agent.
-it shows editors or agents that you have your finger on the pulse of the genre you're writing -- that you're current, that you know what's hot, that you've done your homework.
-it shows that there is a potential readership for your manuscript
-it helps the publisher see where your book might fit in their catalogue
-it helps the editor or agent pitch your manuscript
-it helps you locate the right publisher -- they published that book they may be interested in publishing yours.
-finding and reading that other book might inspire you to rewrite your manuscript or may inspire you to write another manuscript
-it verifies that your manuscript is fresh and original
-it keeps you motivated. You get to see, feel, smell a book that is similar to what yours might look like.
Where do you find these potential comps?
-your bookshelves
-your local library
-your favourite bookstore
-publishers' catalogs
-Quill and Quire magazine
-Publishers Weekly
-Amazon
-Other reviewers who read your genre
Heather Ann Burnell (Submissions 101 - Finding Comparable Books) writes: Use 'titles that are recent [within 10 years] and are in the same category or genre, have the same target audience, and are not so obscure that that the person reading your query has never heard of it' or so popular that you're seen as arrogant or lazy.