Funny that you should say that, because that is exactly what I do -- add inspirational quotes to the back of the bookmarks I make. You can view them on my laserlaura website. The link is below.
A few months ago I attended a writers' conference and to advertise my editing services, I redesigned my business card into a bookmark and left them on the table as giveaways -- also with quotes on the back.
Great minds think alike! ~ Thanks for your comment!