metaphor (n.), a figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable, a thing regarded as representative or symbolic of something else, especially something abstract
The power of the metaphor lies in its ability to communicate the abstract. When you have something complicated to explain, whether it be an emotion or technical process, you don't want to lose your audience to your rambling, literal terminology. Let's consider this blurb from a financial group's website:
As the nation’s largest independent broker-dealer*, a top RIA custodian, and a leading independent consultant to retirement plans, LPL is an enabling partner to more than 13,500 financial advisors and approximately 700 financial institutions. We believe that objective financial guidance is a fundamental need for everyone. Through our proprietary technology and a suite of customized services, we enable our customers to focus on creating the personal, long-term client relationships that are the foundation for turning life’s aspirations into financial realities.
Did your eyes glaze over? Mine did. My brain had nothing to chew on--no image, no idea, no feeling. Instead my brain attempted to gnaw on words that painted a bleak, abstract picture. This will not do if you actually want people to pick you over your competitor. Finance is boring. Most people don't get excited about the terms "broker-dealer," "RIA custodian," or even "financial guidance." Nor do people care about how many advisors, institutions, or services you have. Your audience just wants to get off your finance site as soon as possible, so let them.
Enter the sleek and sexy metaphor:
Nurturing your money, also known as "adulting," can sometimes be severely mind-numbing. In fact, some people find it utterly unbearable. But with LPL, attending to your finances can feel as natural as pulling on your favorite t-shirt. We're the tried and true group that won't disappoint. Let us match you with an advisor who'll fit you and feel better than any tailored suit."
Metaphors are not only useful when attempting to explain something complicated; they're also great for appealing to the senses. Sensory marketing is legit--the more senses you incorporate into a message, the more effective it's proven to be--and metaphors can provide an avenue for including content that evokes sights, sounds, scents, and tastes. When you think of your favorite t-shirt, you think about the comfort of wearing something casual and familiar. You think about the fresh scent of laundry and the softness of something worn over and over again. After walking away from that paragraph, you'll end up remembering that impression for a while.
People tend to shy away from using metaphors when creating "professional" content because they fear metaphors aren't to the point. They might also worry about the irrelevant associations that a metaphor might conjure. My response: what's more important, being completely relevant/on point or being remembered? Humans value uniqueness. Are your competitors going to use this metaphor? No. So use it.