Our group memberships within our society-at-large define us. A subculture is a group whose members share beliefs and common experiences that set them apart from others. Every one of us belongs to many subcultures, depending on our age, race, ethnic background, or place of residence.

The staggering diversity of consumers’ interests and activities today means that it’s usually no longer meaningful to speak of a mass market. We are witnessing a continuing spiral of market fragmentation that requires us to speak with increasingly greater precision to smaller groups of consumers—but the upside is that we can focus our messages very sharply to reach them.

In contrast to larger, demographically based subcultures like Hispanic-Americans or baby boomers (that Nature usually determines), people who are part of a microculture freely choose to identify with a lifestyle or aesthetic preference. A good example is the microculture that automobile hobbyists call “Tuners.” These are single men in their late teens and early 20s, usually in Latino or Asian communities, who share a passion for fast cars, high-tech auto upgrades, and specialized car parts. This microculture started with late night meets among illegal street racers in New York and L.A. Now, Tuners are more mainstream; magazines including Import Tuner and Sport Compact Car and major companies such as Pioneer eagerly court these high-tech hot-rodders. A commercial for the Honda Civic aimed straight for Tuners; it showed a fleet of cars sporting customized features such as chrome rims and tinted windows.

Whether Tuners, Dead Heads, or skinheads, each microculture exhibits its own unique set of norms, vocabulary, and product insignias (think of the Grateful Dead subculture’s distinctive skull and roses). A study of contemporary “mountain men” in the western United States illustrates the binding influence of a microculture on its members. Researchers found that group members shared a strong sense of identity that they expressed in weekend retreats, where they reinforced these ties by using authentic items like tepees, buffalo robes, buckskin leggings, and beaded moccasins to create a sense of community among fellow mountain men.

These microcultures can even gel around fictional characters and events, and they often play a key role in defining our self-concept. Many devotees of Star Trek, for example, immerse themselves in a make-believe world of starships, phasers, and Vulcan mind melds. Our microcultures typically command fierce loyalty: Star Trek fans are notorious for their devotion to the cause, as this excerpt from a fan’s email illustrates:

Star Trek is a merchandising empire that continues to beam up millions of dollars in revenues. Needless to say, it’s not alone in this regard. Numerous other microcultures are out there, thriving on their collective worship of mythical and not-so-mythical worlds and characters ranging from the music group Phish to Hello Kitty. Indeed, it’s fascinating to realize just how many microcultures are out there (often reinforced by our obsession with blogging about anything and everything that we experience) and the products they can coalesce around. Consider, for example, the devotion to Peeps; every year people buy about 1.5 billion of these mostly tasteless marshmallow chicks; about two-thirds of them sell around Easter. They have no nutritional value, but they do have a shelf life of two years. Maybe that’s why not all Peeps get eaten. Devotees use them in decorations, dioramas, online slide shows, and sculptures. Some fans feel challenged to test their physical properties: On more than 200 Peeps Web sites, you can see fetishists skewering, microwaving, hammering, decapitating, and otherwise abusing the spongy confections.

If a homely marshmallow candy can attain icon status in a microculture, might your product be next?