I've used postcard promotion for a number of my books, including The Magic of Patchwork. This included sending out postcards to announce the new release, even printing an order blank on the card. I've also had extra cards printed without order blanks and use them when I correspond with fans, family and friends.
I'm impressed with the use of postcards to announce Jennifer Chiaverini's new Elm Creek Quilts novel, The Union Quilters. Jennifer mentioned on Facebook that she had 20 postcards and a Union Quilters' pin, to send to the first 100 people who responded with an e-mail. She would appreciate their distributing the cards, which announced her new book and listed her upcoming appearances.
I responded in time to receive the cards and have been handing them out to my daughter's quilt group, the local library and a local bookstore where I teach workshops. I'm also mailing them to friends who read the Elm Creek Quilts books and/or are involved in quilting.
Do you have unique ways of using postcards to publicize your books?