A tagline is a slogan that succinctly, memorably, and descriptively sums up a company or product. The art of crafting one is quite complex, and several consulting companies actually specialize in creating taglines for their clients. A well constructed slogan can endure in the minds of consumers for years; some taglines have actually outlived their products. Once a company has a good one, it includes it in all its marketing materials to get it into the minds of consumers so that they think about that company frequently.
A wide range of industries use taglines. Movies are famous for them, and those of many films have entered popular culture, regardless as to the quality of the film itself. Many people refer to “going where no man has gone before,” for example, without realizing that they are referencing Star Trek films. A movie tagline is typically included on its poster and in previews for the film, and famous film franchises may start early campaigns with cryptic posters that only display the slogan for the franchise, and nothing else.
In product advertising, taglines and jingles can make or break a product. Many people remember than M&M's “melt in your mouth, not in your hand” when they're at the candy store, or they “don't get mad, get Glad” when they buy garbage bags. One for a product is usually included in commercials and print advertisements, and sometimes on the product packaging as well, so that if someone remembers hearing about a “quicker picker-upper” on television, he or she can figure out which brand of paper towels the advertisement referred to.
Organizations also use taglines to brand themselves and their family of products. Apple once asked its users to “think different” for example, and Allstate lets its customers know that they're “in good hands.” These slogans are meant to promote a positive overall view of the company in question and to make potential customers feel good about that particular company. Some companies also use tongue in cheek taglines, like “for negative people” for a camera company.
Taglines are so globally pervasive that many people probably would recognized most, if not all, of the companies referenced above by their slogans alone. Most individuals can probably generate a sizable list if they sit down and think about it for a moment, and people might even catch themselves using one in the form of a snowclone in conversation.