I spend a lot of my time, talking to small business owners about their target customers.  We talk about age, income, gender, marital status, and where they live.   But customers are three dimensional beings.  Beyond the numbers which define the demographic segments there is a psychological element as well. This psychological component includes interests, problems, values, philosophy and motivations.  For example:

Interests – What do your potential clients think about? Where do they spend their time? How do they react to things? What’s important to them? What fascinates or intrigues them?

Problems – What do they find annoying, disturbing or frustrating? What are their aversions? What do they dislike? What do they fear?

Values – What do they hold in high regard? Where do they put their time and their money? What are their politics? What do they take a stand about? What and who do they admire?

Philosophy – What is their attitude to life and business? How do they approach challenges? Are they optimistic and accepting or pessimistic and cynical?

Motivations – What makes them take action? Do they move away from things or move towards them? When will they commit to something? When will they ignore advice or accept advice?

The more you know about these psychological elements, the easier it is to write effective marketing copy.   As you create a very specific description which gives your marketing focus, it is important to balance the description with an analysis of the attractiveness (factors such as profitability and potential sales) of the segment.
In this video from my Random Strangers program I talk about how two people in the same demographic segment will have very different psycho graphic profiles and how you can use this information to determine who is most likely to buy from you.