Even the website is for everybody , this postcard is only for the businesses that provides service which could be demonstrated with pictures (renovation, restoration, fitness trainers, cleaning products, cosmetic surgery, fitness products, beauty and skin products, decoration, staging, remodelling like car...)
The front page must be visual that contain the Company logo and copy of website's landing page or some other images or illustration defining the purpose of the site, before and after images of anything. The landing page shows after pictures initially. When the mouse is hovered over an image, the before picture is shown. A design thats gives that feeling will be great.
The back page will include the text and small 1-2-3 steps illustration ( taking before after pictures-> uploading and creating a post -> getting leads )