It sounds counter-intuitive but some new businesses are not sure who their target customers are. They may know who they want them to be (affluent customer from the surrounding geographic area with significant disposable income), but don't always know if their customers will be male or female, what age group, etc. or what their favorite products or services or optimal price points will be.
To learn more about your target customer, visualize the group you want to reach out to and learn more about that group. Where do they shop? What magazines and newspapers do they read? Do they shop online? Is your target customer male or female? married or single? parent or nonparent? These types of things will help you to get a better feel for who your customer is and offer some insight as to where you might be able to reach that customer. For example, if you know your customers have children, you might target a parenting magazine for advertising versus a community newspaper who hits part of that demographic but not all of it. You might also consider adding a children's corner to your store to make it easier for families to bring their kids shopping with them.
Once you define your target market, reach out to those customers and continue to research and tweak your demographics. The better you understand your customer, the more effective your marketing will be. Happy marketing!