Knowing your perfect customer is only the first step in marketing towards them. Knowing where he or she lives is still just an early step. What you need to figure out now is why.
Why does your perfect customer live in a house rather than an apartment? Why do they take public transportation when they could just as easily own a car? Why do they buy groceries ten miles away when they live next door to a supermarket? This information is called psychographics, and it can tell you much more about your customer than anything else can.
What you are looking at is behavioral drivers, the explanations behind your customers' actions. Here is a simple illustration. Client A and Client B live next door to one another. They drive the same cars, make the same amount of money in a year, and watch the same television shows. Demographically, the two are identical. Client A is concerned about low food prices, so he drives across town to the cheapest supermarket. Client B is concerned about global warming, so he drives across town to a supermarket that boasts its energy efficiency and focus on "green" products.
Both Clients A and B shop at the same grocery store, but for very different reasons. If you want Client A to buy your products, you would work for the lowest possible price. You would then advertise the bargain your products are compared to the competition. If you instead want Client B, you would work for the most environmentally sustainable product offering and advertise it as such. You would choose either strategy based on the nature of your products: a computer manufacturer might choose price (low prices do not have much negative effect on a computer brand). The manufacturer of high-end fashionable suits, however, would choose sustainability (the price of a suit is as important to the brand image as the name on on the cuff).
Step one: Know your customer (Identification)
Step two: Define your customer (Demographics)
Step three: Understand your customer (Psychographics)
Step four: Market to your customer (Communication)
This is a linear system, and you cannot skip steps without severe repercussions. Client A would not buy an expensive green product; investing in marketing towards him would be a colossal waste of money and would hurt your business. If skipping steps wastes money, why jump the gun?