You mean that blue button on your home page? It's a portal to a constantly expanding supply of templates for postcards you can print at your leisure. You can also find the postcards by selecting your "Resources" tab at the top of your desktop, and then selecting Witty Postcards. Each postcard will be available in multiple sizes for standard mail, and for Every Door Direct Mail (EDDM). You'll also find suggestions for text to place on the back of the card.
Be sure to check back regularly as we are adding new postcard templates all the time.