The DOPE way to deliver the pieces of your BLITZ is to stagger them slightly, and make them refer to each other. For instance, if you send a postcard, you should follow up the postcard with a ringless voicemail that refers to the coupon on the postcard. Then, you should place yard signs in prominent corners of the neighborhood that you are targeting, with the same offer on it that you had on your postcard and in your ringless voicemail. Who could say no?