Do you know who your customers are? How do you know? There is a lot of easy data you can get from places like your Facebook Fan Page Insights. But what do these Insights tell you? They only tell you who Like's your page. Since your pages will always be a fraction of your customers, don't rely on this data to determine who your demographic is. If you are brick and mortar, you can study your customers in real life to determine this.
Here is the Insights page for my a client. They are brick and mortar business. My client knows from working with me that Social Media helps her business but does not drive her business. We did a study in December that showed that over 80% of her customers do not follow on the Twitter or like her page on Facebook.
Here is her demographic page:
Looking at this you would think this is the demographic breakdown for her real life customers. In fact over 50% of her sales are Male 18 to 34. This is why services such as Klout have limited basis in reality. You do not know who is behind the computer or interacting with you in reality or their true influence in their world.