Back when I used to sell paper goods offline I ordered a stamp and stickers from Vistaprint.com with my name on it - if you keep your eye out they often have deals on groupon.com and livingsocial.com for Vistaprint, and the site itself has great promos all the time. I just wanted to share because I have been so happy with them every time I've bought from them (now business cards, stickers, and sticky notes for my Etsy shop) and it is always important to keep your branding consistent. I think I liked the stamp idea better because it always was in the back of my mind that someone could take the little sticker off (not sure why they would, but it always bugged me! haha)
I know that when I buy something on Etsy, most times someone asks me where I got such a beautiful creation and if there is a tag or signature, then I get to advertise for the lovely shop I bought it from! Most people tend to lose track after a while, so it's good to remind them with your branding (:
Your books are really lovely, by the way! <3