Mental fluency is similar to the thickness of a liquid. Short, easy-to-pronounce words are swallowed like water, whereas long, complicated words are swallowed like honey. Although honey still goes down, it takes more effort.
Our brains are built to treat more fluent words, ideas, images, and sounds with a higher priority than their less-fluent counterparts. In other words, our brains drink the water before they swallow the honey. As a result, we tend to remember short, punchy political slogans and we tend to forget long, complicated prayers and poems. With better memory of these “highly fluent” slogans comes a familiarity, a trust, and a willingness to spread.
To build fluency into your product, remove the friction associated with deciphering and remembering your core message. Simplify it as much as possible. When compared to a competing message, your customers will remember and believe the one that is easier to remember. Popular political slogans gain their virality through this single psychological principle.