Rack cards (or marketing cards) are generally tall and narrow and got their name for fitting nicely in a display. They are often used to target prospective customers or guests in areas with heavy foot traffic, like a tourist kiosk, tradeshow, or conference and drive people to your website
The major difference between a rack card and a brochure, which is what most people are familiar with, is that it’s generally cheaper to print a rack card. Having a rack card professionally designed costs less because it’s one sliver of paper, usually double-sided; not three panels that are double-sided, like a brochure.
If you really want someone to keep your information handy, a rack card boosts that chance. The paper they’re printed on is heavier. People will pick up a rack card and flip it over, look on both sides for information.