I know sending actual mail is expensive, but email is so in-tangible; and not very effective. Because of this, I like to send something once a year to mix up my recipe postcards and holiday cards. Last year I sent out a magnet.
I recently ordered 500 notepads ($240) from Easy Street Designs to send out to my database. I personally love this size note pad. I keep them by my fridge for a grocery list, in my desk and on my night stand.