If you aren’t doing so already, casually survey all clients before they cash out. Kindly request their permission to ask them basic questions about their occupation, their use of time, the reason why they’re in front of you, what they like (and would improve) about their experience, and so on. This will give you a better idea of who comes to your store and why. Train your staff to do the same. Ask the same questions of everyone.
Tip: You don’t have to ask a flurry of questions from every customer that walks through your doors. Ask a single question of every customer one week, another question the next, and so on, and you will begin to shape a picture about the people who shop from you.