It's human nature: When we design products, we often design for ourselves. Sometimes, when your strategic planning is perfectly aligned with the needs of your customers, this can work well. But other times it means you're missing critical nuances and the opportunities they present. "We call that self-centered design," said Phillip Djwa, founder and principal of Agentic Digital Media, a web development agency that works with many middle market companies.

That's why the development of "personas," a process he often leads with clients, is important. "It's a simple way for businesses to align their marketing efforts by inventing archetypical users," Djwa said.

Developing these personas came to public attention a decade ago, when it was revealed that Best Buy grouped its customers into categories such as "Jills" (soccer moms who are intimidated by electronic stores) and "Barrys" (wealthy professional men). This strategic planning technique is beneficial, said Djwa, because "it helps us keep attuned to the fact that actual human beings will be using our software or websites" or products. "They put a face on the user, and act as a design target for everyone involved."

Because, he said, let's face it: "Reading long market research reports doesn't always translate to all the graphic designers, communication folks, and programmers in a way that they can absorb. A well-crafted persona is a useful and lively way of capturing and describing user needs for everyone."

Additionally, it's an alignment tool. Let's say you're creating a new product or service. "If you asked each stakeholder to describe a user," he said, "each would probably describe someone quite different. By developing personas together, we get the best of the thinking distilled into personas we all agree on."

So how do you go about building personas to better understand your customers? It starts with market research, such as interviews, customer feedback, staff interviews, and surveys, said Djwa. "I believe that a company should know its target audience quite well before developing a persona."

Next, you develop a list of attributes. For instance, some customers are nervous about visiting electronic stores, and others love them. Some research assiduously before making a purchase, while others splurge on impulse buys. Then, he said, "using the attributes, we segment the audience into behavioral 'chunks' or segments. And based on these segments, we craft one or two personas that reflect key tasks and motivations for a typical user from each segment."

Thus, we get personas like Best Buy's "Jill," which resulted in those customers receiving extra love from associates to assuage their concerns about making a complicated and expensive technology purchase.

Djwa advises his clients to limit the number of personas they develop in their strategic planning. "I tend to develop three to five," he said. "If there are more than that, chances are, it's too much to focus on. Also, most clients can really target only a few key segments with enough resources and thoughtfulness to be useful."

The process of developing the personas can be extremely useful in helping companies understand the nuances of their customer base. "Oftentimes, a persona can be described fairly easily by our clients or it emerges from the market research," he said. But every once in a while, there's a surprise. "The discovery comes when we identify a segment that wasn't previously obvious to the client. It's almost like meeting a new friend: 'Oh, have you been there all this time? Pleased to meet you!'"

The ability to target this previously unrecognized customer segment can lead to major new opportunities. Overall, said Djwa, personas draw valuable attention to the customer experience and how to improve it. "I know that people often invest personally when the persona starts to become more real," he says. "We start to even talk to them and address them in our meetings. It's an incredibly powerful way to bring the voice of the customer to the table."

Dorie Clark is an NCMM contributor and a marketing strategist who teaches at Duke University's Fuqua School of Business. Learn more about her new book Reinventing You: Define Your Brand, Imagine Your Future (Harvard Business Review Press). Follow her on Twitter.